Russian/Soviet Ordnance Fuze Encyclopedia

CRITICAL REFERENCE: This file is the single most important document in this database for Render Safe Procedure (RSP) decisions. Fuze type determines approach protocol, hazard assessment, and disposal method.

Classification: OPEN SOURCE / OSINT compilation Source Rating Methodology: Per SOURCE_RATING.md (NATO-aligned OSINT grading) Statistical Standards: Per STATISTICAL_STANDARDS.md -- dud/failure rate data uses formal statistical reporting where N is available; otherwise estimation standard applies. Last Updated: 2026-03-28

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TABLE OF CONTENTS

1. Mortar/Artillery Nose Fuzes
   • V-429 / V-429E
   • RGM-2 / RGM-2M
   • M-6 / GVMZ Series
   • AR-5 (Proximity)
   • AR-139 (Proximity)
   • T-7 / T-90 (Time)
   • 9E246 / 9E246M / 9E272 (Submunition)
   • 9E156 "Zont" (Laser Proximity)
2. Base Fuzes
   • MD-5 / MD-7 / MD-8 / MD-10
   • DBT (All-Ways Acting)
   • DBR (Base Detonating)
3. Bomb Fuzes
   • AVU-ET / AVU-ETM (Universal Nose/Tail)
   • AVB-E (Nose/Tail Impact)
   • TM-24B (Mechanical Time)
4. Grenade Fuzes
   • UZRGM / UZRGM-2 (Hand Grenade Delay)
   • VMG-K (VOG-25 Impact)
   • VMG-M-L (VOG-17 Impact)
5. Mine Fuzes
   • MV-5 (Pressure)
   • MVE-72 (Electronic Breakwire)
   • MUV / MUV-2 / MUV-3 (Pull/Push)
   • VP-13 (Seismic/Electronic)
6. Missile/Rocket Fuzes
   • MRV / MRV-U (9E210/9E244) - Grad
   • 9E244 - Uragan
   • Smerch Rocket Fuzes
7. Cross-Reference: Fuze-to-Ordnance Matrix
8. EOD Decision Framework

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1. MORTAR/ARTILLERY NOSE FUZES

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V-429 / V-429E

The Most Common Russian Point-Detonating Artillery Fuze

Designation: V-429 (B-429); Enhanced variant: V-429E (B-429E) NATO reporting: PD fuze, impact, superquick/delay Source: Arcus JSC, Armaco JSC, Romarm manufacturer datasheets; CAT-UXO; METIS/Fenix Insight [Rating: A-1 -- manufacturer data confirmed by multiple independent databases]

1. Designation and Variants

2. Physical Description

• Weight: 438 g
• Intrusion length: 46.8 mm (depth into projectile well)
• Thread: Standard 56mm Soviet fuze well thread
• Body: Steel, typically with olive drab or bare metal finish
• Construction: Two-part body; nose cap covers the striker mechanism
• Visual features: Hexagonal wrench flats on body for installation; setting ring visible between nose cap and body; Cyrillic markings stamped on body (designation, lot number, year)

3. Arming Mechanism

• Type: Inertia (setback) armed
• Process: At firing, setback forces drive the safety/arming device (S&A), aligning the detonator with the fire train. A setback sleeve releases and the rotor or slider moves into alignment.
• Key safety feature: Before firing, the S&A device prevents the detonator from positioning into the fire train. Even if the primer is accidentally ignited, no transfer of the firing pulse to the fire train can occur.

4. Function Type

• Position "O" (O for "Oskolochnyy" / fragmentation): Super-Quick (SQ) -- instantaneous detonation on impact
• Position "3" (Z for "Zamedleniye" / delay): Delayed action -- 0.027 to 0.063 seconds after impact
• Graze function: Yes -- the V-429E specifically provides PD, graze, and delay functionality

5. Arming Distance/Time

• Arming distance: 5 to 20 m from muzzle
• Mechanism: Complete within first few milliseconds of setback acceleration

6. Self-Destruct Feature

• Self-destruct: NO
• The V-429 has NO self-destruct mechanism. If it fails to function on impact, it remains armed indefinitely.

7. SAFE/ARMED Indicators

• SAFE: Setting ring in factory position; no evidence of firing (no barrel wear marks on rotating band of parent projectile)
• ARMED: After firing, there is NO positive external visual indicator of armed status. Assume armed if projectile shows any evidence of having been fired.
• Setting position: "O" or "3" visible on the setting ring -- indicates selected function mode but NOT safe/armed status

8. Sensitivity

• Impact angle range: Functions across wide range of obliquity angles; graze function on V-429E ensures function even at very shallow impact angles
• G-force threshold: Requires standard artillery setback forces (~5,000-15,000 G depending on weapon system)
• Terrain sensitivity: Functions on all terrain types including soft ground, snow, and marshy conditions in SQ mode

9. Ordnance Cross-Reference

10. EOD CRITICAL

WARNING: EXTREMELY HAZARDOUS IF ARMED

• Can it be rendered safe? Fuze removal is POSSIBLE on unfired rounds. On fired rounds where the fuze has armed, fuze removal is the standard RSP approach IF the projectile is stable, fuze well is not damaged, and there is no evidence of partial function.
• General approach: For UXO (fired, failed to detonate):
  • Assess fuze setting (O or 3)
  • Check for evidence of partial function (cracked nose, displaced setting ring)
  • If no evidence of partial function and projectile is stable: remote fuze removal may be attempted using approved fuze wrench and pull procedures
  • If ANY doubt: BIP (Blow In Place)
• BIP threshold: Low threshold for BIP. This fuze is simple and reliable; failures are uncommon and usually indicate mechanical damage that makes the fuze LESS predictable.

11. Known Failure Modes

• Low-angle impact: Projectile skips or ricochets without generating sufficient deceleration to function the striker -- results in armed UXO that may function on secondary movement
• Soft ground burial: Projectile buries in soft soil/mud without sufficient deceleration; fuze armed but unfunctioned
• Mechanical damage: Damaged striker mechanism or fire train misalignment from rough handling
• Worn barrel firing: Manufacturer notes "locking at firing from worn-out or strongly contaminated barrel" as a known issue -- may result in improper arming

12. Hazard Warnings

• ARMED STATUS NOT VISUALLY DETERMINABLE on fired rounds -- treat all UXO with V-429 as armed
• Delay setting creates additional hazard -- if set to "3", the fuze may have initiated its delay train but not completed detonation; a partially initiated delay element is extremely sensitive
• DO NOT attempt to change the setting ring on a fired round -- the setting mechanism interfaces with the fire train
• Temperature sensitivity: Functions reliably across -50C to +50C; extended exposure to extreme heat may degrade pyrotechnic elements unpredictably
• V-429E graze function means this fuze can detonate at impact angles that would cause a standard PD fuze to skip -- larger hazard radius for graze-sensitive items

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RGM-2 / RGM-2M

Standard Russian Impact Fuze for Medium/Heavy Artillery

Designation: RGM-2 (PГМ-2); Modernized: RGM-2M Source: CAT-UXO, METIS/Fenix Insight, Arcus JSC, Kintex, VMZ-Sopot [Rating: A-1]

1. Designation and Variants

2. Physical Description

• Construction: Two-part steel body; front section screws into rear section
• Front section: Cadmium-plated surface (bright/silvery appearance)
• Rear section: Surface treated -- blacked, phosphated, or similar dark coating
• Visual distinction: Two-tone appearance (bright nose, dark body) is a key identification feature
• Thread: Standard 56mm Soviet fuze well

3. Arming Mechanism

• Type: Inertia (setback) armed
• Process: Setback forces at firing align the fire train components
• Arming distance: 5 to 20 m from muzzle

4. Function Type

• Position "O": Super-Quick (SQ) action
• Position "3": Delayed action -- 0.027 to 0.063 seconds
• Setting method: Built-in setter and wrench
• Graze function: Yes -- functions on oblique impact

5. Arming Distance/Time

• Arming distance: 5 to 20 m from muzzle
• Arming force: Standard artillery setback

6. Self-Destruct Feature

• Self-destruct: NO

7. SAFE/ARMED Indicators

• Same as V-429: No positive external armed indicator on fired rounds
• Setting ring: Shows selected mode (O or 3)
• Two-tone body: The cadmium/dark finish pattern should be intact on unfired fuzes; blast residue or damage indicates firing

8. Sensitivity

• Impact sensitivity: Functions on solid ground, semi-hard ground; graze function on oblique impact
• Delay accuracy: 0.027 to 0.063 seconds

9. Ordnance Cross-Reference

10. EOD CRITICAL

• RSP approach: Identical to V-429. Remote fuze removal possible if stable and no partial function evidence.
• BIP: Low threshold for BIP on any item showing damage or partial function.

11. Known Failure Modes

• Same as V-429: low-angle skip, soft ground burial, mechanical damage
• The two-part body construction can fail at the screw joint under extreme impact, potentially causing partial separation without detonation -- resulting in a HIGHLY SENSITIVE UXO

12. Hazard Warnings

• Identical hazard profile to V-429
• Additional warning: The cadmium plating on the nose section is toxic; avoid skin contact with corroded specimens
• Two-part body: If the front and rear sections have visibly separated or shifted, the fuze is in an UNPREDICTABLE state -- BIP only

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M-6 / GVMZ Series

Standard Russian Mortar Fuzes

Designation: M-6 (M-6), GVMZ, GVMZ-1, GVMZ-7 Source: Arcus JSC, CAT-UXO, Fenix Insight, WW2 Data [Rating: B-2]

1. Designation and Variants

2. Physical Description

• GVMZ-7 overall length: 103.6 mm (cap removed)
• GVMZ weight: ~430 g
• Construction: Steel body, nose cap covers striker
• GVMZ-7 distinction: Uses adiabatic (air compression) detonation principle rather than conventional striker/pin

3. Arming Mechanism

• M-6: Setback armed on firing; mortar propellant acceleration provides setback force
• GVMZ-7: Adiabatic principle -- uses rapid air compression on impact to achieve detonation temperature; armed by setback
• GVMZ/GVMZ-1: Setback armed with selectable SQ/delay

4. Function Type

• M-6: SQ only
• GVMZ/GVMZ-1: Two settings -- (1) Instantaneous/SQ and (2) Delay
• GVMZ-7: Instantaneous and delay settings

5. Arming Distance/Time

• Estimated: 20-100 m from muzzle (mortar fuzes require lower setback than artillery fuzes due to lower acceleration)

6. Self-Destruct Feature

• Self-destruct: NO (none of the GVMZ/M-6 series have self-destruct)

7. SAFE/ARMED Indicators

• Cap in place: Generally indicates shipping/storage configuration
• No positive armed indicator after firing

8. Sensitivity

• Designed for mortar impact velocities (lower than artillery): typically 100-300 m/s terminal velocity
• Functions on soft ground at designed impact angles (steep, typically 45-85 degrees)

9. Ordnance Cross-Reference

10. EOD CRITICAL

• GVMZ-7 is particularly hazardous: The adiabatic fuze uses no conventional striker mechanism -- detonation occurs through rapid air compression. This means there is no conventional fire train to interrupt.
• M-6/GVMZ: Standard fuze removal RSP applicable if stable
• GVMZ-7: Higher threshold for RSP; BIP preferred

11. Known Failure Modes

• Low-velocity impact: Mortar rounds at minimum charge that fail to achieve sufficient terminal velocity may not generate enough deceleration for the striker/adiabatic mechanism
• Soft ground/deep burial: Very common with mortar rounds due to steep trajectory and relatively low velocity
• Dud rate for mortar fuzes historically higher than artillery fuzes due to lower and more variable impact energies

12. Hazard Warnings

• 82mm and 120mm mortar UXO are among the most common items encountered in post-conflict environments
• Mortar bombs are inherently less stable than artillery projectiles when found as UXO -- body may be damaged, fins bent, fuze exposed
• GVMZ-7 adiabatic fuze: any sharp blow or compression of the fuze nose can theoretically initiate the air column -- extreme sensitivity hazard

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AR-5

Russian Radio-Frequency Proximity Fuze

Designation: AR-5 (AP-5) Source: Fenix Insight/METIS, Inert Products LLC [Rating: B-2]

1. Designation and Variants

2. Physical Description

• Type: Electro-pyrotechnically armed, radio-frequency proximity fuze
• Body: Larger than standard PD fuzes; contains RF oscillator and battery
• Visual features: Antenna ring/band visible on fuze body; electronic components

3. Arming Mechanism

• Type: Electro-pyrotechnic arming
• Process: Setback and spin forces activate a battery (reserve battery -- electrolyte activated by spin); pyrotechnic delay then completes arming sequence
• Dual safety: Requires BOTH setback forces AND spin (centrifugal) forces
• Electronic arming: Battery must reach operational voltage before proximity circuit activates

4. Function Type

• Primary: Radio-frequency proximity (airburst at preset height above ground)
• Backup: Point-detonating (PD) impact function
• Height of burst: Variable, set before firing
• Two HoB settings available

5. Arming Distance/Time

• Estimated: Several hundred meters (typical for proximity fuzes -- longer than PD fuzes due to electronic warm-up)

6. Self-Destruct Feature

• Self-destruct: Battery depletion renders the proximity function inoperable after flight time exceeds battery life; however, the PD backup function may remain viable

7. SAFE/ARMED Indicators

• Battery activation is irreversible -- once the reserve battery has been spun up and electrolyte released, it cannot be "un-armed"
• No external visual safe/armed indicator

8. Sensitivity

• Proximity sensitivity: Tuned to detect ground reflection; may also trigger on vehicles, structures, vegetation
• PD backup: Standard impact sensitivity

9. Ordnance Cross-Reference

10. EOD CRITICAL

WARNING: PROXIMITY FUZES ARE AMONG THE MOST DANGEROUS UXO ITEMS

• Can it be rendered safe? EXTREMELY DIFFICULT. The RF proximity circuit may still be active if the battery has charge. Any conductive object approaching the fuze (including the human body or metal tools) may trigger the proximity circuit.
• General approach: DO NOT APPROACH with metal tools or equipment. Remote BIP is the STRONGLY PREFERRED method.
• If RSP is absolutely required: Non-metallic approach only; RF shielding considerations; only by personnel trained specifically in proximity fuze disposal.

11. Known Failure Modes

• Battery failure: Reserve battery fails to activate or dies before reaching target area -- round impacts with PD function only (or as complete dud if PD also fails)
• RF circuit failure: Proximity circuit malfunctions but PD backup functions normally
• Premature burst: Proximity circuit triggers on intervening objects (trees, structures, rain, chaff) before reaching target
• Complete dud: Both proximity and PD functions fail -- item is armed with live battery, making it EXTREMELY hazardous

12. Hazard Warnings

• DO NOT APPROACH proximity-fuzed UXO with metal objects -- RF proximity circuit may interpret approaching metal as a target
• Battery may retain charge for hours to days after firing -- do not assume battery is dead
• RF emissions from the fuze may interfere with radio communications equipment and vice versa -- maintain radio silence within the hazard zone
• Rain, vegetation, or irregular terrain may have caused premature function -- but also may have caused the round to land without functioning, leaving a fully armed item

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AR-139

Modern Russian Proximity Fuze (Improved)

Designation: AR-139 (AP-139) Source: Arcus JSC, Kintex, Armaco JSC manufacturer data [Rating: A-1]

1. Designation and Variants

2. Physical Description

• Type: Radio-frequency proximity fuze with mechanical arming
• Thread: Standard 56mm Soviet fuze well

3. Arming Mechanism

• Type: Mechanical arming by TWO independent mechanisms:
  • (a) Setback forces -- minimum 2,000 G acceleration required
  • (b) Spin -- minimum 3,500 RPM required
• Electronic arming: Minimum 0.6 seconds after firing
• Safe separation distance: 40 m from muzzle

4. Function Type

• Primary: Proximity (PRX) -- airburst
• Backup: Point-detonating (PD) on impact
• Nominal height of burst: 4 m above target (average); other HoB settings available on request
• Minimum flight time for proximity function: 2.4 seconds

5. Arming Distance/Time

• Safe separation distance: 40 m minimum
• Electronic arming time: 0.6 seconds minimum
• Proximity function available after: 2.4 seconds flight time

6. Self-Destruct Feature

• Self-destruct: Not specified in available data

7. SAFE/ARMED Indicators

• Dual mechanical arming: Requires both high G-force AND spin; unlikely to arm from accidental drop or impact
• No positive external indicator

8. Sensitivity

• Setback threshold: 2,000 G minimum
• Spin threshold: 3,500 RPM minimum
• Proximity detection: Optimized for 4m HOB over flat terrain

9. Ordnance Cross-Reference

10. EOD CRITICAL

• Same extreme hazard as AR-5 -- proximity-fuzed UXO requires remote BIP as first option
• Higher arming thresholds (2,000G / 3,500 RPM) provide slightly better safety against accidental arming compared to older proximity fuzes
• PD backup means even a proximity dud may still detonate on handling

11-12. Failure Modes and Hazards

• Same categories as AR-5 proximity fuze
• Additional: The dual-mechanism arming provides better safety but when both mechanisms have armed, the fuze is FULLY functional and extremely dangerous

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T-7 / T-90

Russian Mechanical Time Fuzes

Designation: T-7 (T-7), T-90 (T-90) Source: METIS/Fenix Insight, Bulletpicker fuze handbooks [Rating: B-2]

1. Designation and Variants

2. Physical Description

• T-7: Larger fuze with powder ring time train and impact mechanism; visible time setting ring graduated in seconds
• T-90: Small fuze with igniferous (flame) output; designed to ignite expulsion charges for cargo/illumination rounds; visible time setting dial
• Both: Time setting mechanism visible as a graduated ring or dial on the fuze body

3. Arming Mechanism

• T-7: Setback armed; powder time train ignited at firing by flash from propellant
• T-90: Setback armed; time mechanism initiated at firing

4. Function Type

• T-7: Dual -- selectable TIME or SUPERQUICK (impact)
  • Time mode: Powder train burns for preset duration, then fires detonator
  • SQ mode: Functions as standard impact fuze
• T-90: TIME ONLY -- no impact backup
  • Igniferous output only (fires propellant expulsion charge, not a detonator)
  • Used for illumination, smoke, cargo (submunition dispensing) rounds

5. Arming Distance/Time

• T-7: Armed at firing by setback; time train begins burning immediately
• T-90: Armed at firing; timing begins at launch

6. Self-Destruct Feature

• T-7: Time function acts as de facto self-destruct (round detonates when time train burns through regardless of impact)
• T-90: Not applicable (igniferous output for expulsion, not detonation)

7. SAFE/ARMED Indicators

• Time setting visible: Graduated ring shows set time delay
• T-7: If found as UXO, the time train may have burned through without functioning -- EXTREMELY HAZARDOUS as the detonator may be in a partially initiated state
• T-90: If the round did not open/dispense, the fuze timing has passed and the item may be in an unstable state

8. Sensitivity

• T-7 in SQ mode: Standard impact sensitivity
• T-7 in TIME mode: Not impact sensitive (functions on time only) -- but the round itself still contains a detonator and booster
• T-90: Not impact sensitive

9. Ordnance Cross-Reference

10. EOD CRITICAL

• T-7 UXO WARNING: If found as UXO, the powder time train may be in an unknown state -- burned through, partially burned, or extinguished. A partially burned time train may spontaneously re-ignite or may have left the detonator in a near-initiation state.
• T-7 RSP: BIP PREFERRED. If RSP required: remote fuze removal only.
• T-90 UXO: Less hazardous from the fuze perspective (igniferous only), but the cargo/submunitions may be armed and the expulsion charge may be unstable.

11. Known Failure Modes

• Time train extinguishment: Moisture, manufacturing defect, or damage causes the powder train to go out before reaching the detonator -- results in a round with a partially burned pyrotechnic train (UNSTABLE)
• Mechanical timing failure: Clockwork or time ring mechanism jams, preventing function at set time
• Dud time fuze rounds are particularly dangerous because the failure state is opaque -- the internal pyrotechnic condition cannot be assessed externally

12. Hazard Warnings

• TIME FUZE UXO IS AMONG THE MOST UNPREDICTABLE -- the internal state of the time train is unknown
• DO NOT assume that because the set time has elapsed, the fuze is "safe" -- it may have a partially burned, extremely sensitive time train
• T-7 in SQ mode: Treat identically to V-429/RGM-2 PD fuze

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9E246 / 9E246M / 9E272 (Submunition Fuzes)

Critical Submunition Impact Fuzes -- High UXO Hazard

Designation: 9E246 (9Э246), 9E246M (9Э246M), 9E246Mbv, 9E272 (9Э272) Source: ARES (Armament Research Services), Fenix Insight, CAT-UXO, Inert Products [Rating: B-1 -- extensively documented in Ukraine conflict]

1. Designation and Variants

2. Physical Description

• Type: Small, nose-mounted impact fuzes for HE-FRAG submunitions
• 9N210 submunition: Cylindrical body with ribbon-type drag device
• 9N235 submunition: Cylindrical body with six spring-loaded stabilizing fins; length 263mm, diameter 65mm, weight 1.75kg
• Fuze is integral to the submunition nose -- small, recessed into the nose cavity

3. Arming Mechanism

• Type: Pyromechanically-delayed arming
• Process: Upon ejection from the cargo warhead, a pyrotechnic delay begins. After the delay burns through, the arming sequence completes and the fuze becomes live.
• Stabilization: 9N210 uses ribbon drag; 9N235 uses spring-loaded fins to orient nose-down

4. Function Type

• Primary: Point-detonating direct impact
• Self-destruct (where fitted): Pyrotechnic self-destruct timer activates at ejection; if primary function fails, SD detonates the submunition after the specified time

5. Arming Distance/Time

• Arming delay: Pyrotechnic delay begins at ejection from carrier; arming complete within seconds of ejection
• Designed for: Function at terminal velocity after descent from carrier warhead opening altitude

6. Self-Destruct Feature

EOD CRITICAL: Self-Destruct Reliability

Estimate: Submunition self-destruct mechanisms fail at rates far exceeding manufacturer claims. Based on: Manufacturer claims 1-2% combined dud rate. Mine clearance specialists and field observations in Ukraine and Syria consistently report 10-30% failure rates for submunitions in real-world conditions. Supporting evidence: Human Rights Watch reporting (B-1), GICHD Explosive Ordnance Guide for Ukraine 2022 (A-2), ARES field documentation (B-1) Caveats: Exact failure rates by specific fuze variant are not available with statistical rigor. Rates are aggregate across submunition types and conflict conditions. Survivorship bias likely -- failed submunitions that self-destructed after an observer left are not counted.

7. SAFE/ARMED Indicators

• Armed submunitions have completed their arming sequence and will NOT have any visible "safe" indicator
• Fins deployed (9N235): If spring-loaded fins are extended, the submunition has been ejected and the arming sequence has initiated
• Ribbon deployed (9N210): If the drag ribbon is visible, ejection has occurred
• Intact nose: Impact fuze in nose position
• Self-destruct timing has elapsed: If found after SD time has passed and item has not detonated, the SD mechanism HAS FAILED -- the item is armed with a failed self-destruct, making it DOUBLY hazardous

8. Sensitivity

• Direct impact on nose required for primary function -- designed for terminal velocity impact on relatively hard surfaces
• Soft ground, snow, water, or extremely shallow impact angles may prevent function
• Handling sensitivity of armed submunition: HIGH -- any significant shock or acceleration may cause function

9. Ordnance Cross-Reference

10. EOD CRITICAL

SUBMUNITION UXO IS THE SINGLE MOST DANGEROUS CATEGORY OF ITEMS IN CURRENT CONFLICTS

• Can it be rendered safe? NO standard manual RSP. These are BIP ONLY items.
• Why: Small size, sensitive impact fuze, possible failed self-destruct mechanism, unpredictable internal state, no external safe/armed indicators, designed to function on minimal impact
• Approach: Remote procedures only. Consolidation for BIP by remote means (robotic, hook-and-line). NEVER manually handle.
• 9E246 (no SD) submunitions: These remain armed INDEFINITELY with no time limit on hazard
• 9E246M/9E272 (SD equipped) duds: The FAILED self-destruct adds an additional unpredictable pyrotechnic element -- the SD charge is present but has not functioned, creating a secondary sensitivity

11. Known Failure Modes

• Primary function failure: Impact on soft ground, snow, water, vegetation; impact at insufficient velocity; impact at extreme obliquity; mechanical damage during ejection
• Self-destruct failure: Pyrotechnic delay extinguishment; manufacturing defects; moisture ingress; exposure to extreme temperature
• Ejection failure: Submunitions fail to separate from carrier -- entire cargo warhead impacts intact with full submunition payload (EXTREME hazard)
• Partial ejection: Some submunitions eject; others remain in warhead section

12. Hazard Warnings

• THESE ARE THE ITEMS KILLING AND MAIMING THE MOST CIVILIANS IN POST-CONFLICT ENVIRONMENTS
• Submunitions may be scattered over areas of 1-2 hectares per rocket -- area must be systematically surveyed
• 9N235 with deployed fins resembles a small shuttlecock -- distinctive visual profile aids identification but children may mistake for toys
• 9N210 with drag ribbon -- ribbon may be caught in vegetation, making the submunition hard to see
• DO NOT kick, throw, step on, or handle submunitions -- the impact fuze requires minimal force to function once armed
• Weather effects: Rain and temperature cycling can degrade pyrotechnics, making dud submunitions MORE sensitive over time, not less

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9E156 "Zont"

Russian Laser Proximity Fuze for Submunitions

Designation: 9E156 (9Э156), Codename: "Zont" (Зонт / "Umbrella") Source: METIS/Fenix Insight [Rating: C-3 -- limited open-source data]

1. Designation and Variants

2. Physical Description

• Type: Laser height-of-burst sensing fuze
• Used with: 9N730 HE-FRAG submunitions (thought to be)
• Function: Detects height above target surface using laser ranging; triggers detonation at optimal height for fragmentation effect

3. Arming Mechanism

• Electronic arming post-ejection from carrier
• Laser sensor activates after arming delay

4. Function Type

• Proximity (laser): Airburst at optimized height above ground
• Likely PD backup (unconfirmed in open source)

5-8. Limited Data

• Open-source data is limited for this fuze system
• Arming distance/time, self-destruct details, sensitivity thresholds: Not available in open-source reporting

9. Ordnance Cross-Reference

10. EOD CRITICAL

• Treat as proximity-fuzed submunition -- combined hazards of proximity fuze AND submunition
• BIP ONLY -- no manual RSP
• Laser emitter may still be active if battery has charge -- eye safety hazard in addition to explosive hazard

11-12. Failure Modes and Hazards

• All submunition hazards apply (see 9E246/9E272 section)
• Additional laser proximity hazards: Similar to RF proximity fuzes -- approaching objects may trigger function
• Eye safety: Active laser emitter poses direct eye hazard to approaching personnel

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2. BASE FUZES

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MD-5 / MD-7 / MD-8 / MD-10

Standard Russian Base-Detonating Fuzes

Designation: MD-5, MD-7, MD-8, MD-10 (MД-5, MД-7, MД-8, MД-10) Source: Bulletpicker Russian Fuze Handbook, CAT-UXO, Fenix Insight [Rating: B-2]

1. Designation and Variants

2. Physical Description

• Location: Screwed into the base of the projectile (opposite end from nose)
• Body: Steel, threaded into the projectile base plug
• Not externally visible when projectile is intact -- fuze is concealed within the projectile base
• Typically identified only when the projectile base is visible (broken projectile, separated base plug)

3. Arming Mechanism

• Type: Setback armed
• Process: Setback sleeve holds the primer carrier away from a fixed firing pin during storage and handling. Upon firing, setback forces drive the sleeve rearward, freeing the primer carrier to move forward against the firing pin on impact.
• Spin may also be required for some variants (centrifugal arming component)

4. Function Type

• Base detonating (BD): Functions on impact through deceleration of the firing pin/primer assembly
• Delay: Most MD-series base fuzes incorporate a pyrotechnic delay element to allow projectile penetration before detonation
• Designed for: Penetration of light armor, field fortifications, and structures before detonation

5. Arming Distance/Time

• Armed by setback at firing -- armed within the barrel
• Delay allows penetration before detonation

6. Self-Destruct Feature

• Self-destruct: NO

7. SAFE/ARMED Indicators

• Not visible externally when projectile is intact
• If base plug is exposed: Look for displacement of internal components, which may indicate arming

8. Sensitivity

• Requires significant deceleration (impact with hard target) to function
• Designed for anti-armor/penetration role -- may not function on soft ground impact

9. Ordnance Cross-Reference

10. EOD CRITICAL

• Base-fuzed projectiles that fail to detonate are typically DEEPLY BURIED in the target or terrain
• RSP: Generally, base-fuzed AP projectiles require remote BIP. Fuze is not accessible without extensive handling of the projectile.
• If projectile is exposed with base visible: Do not attempt to unscrew base plug or fuze. BIP.

11. Known Failure Modes

• Impact on soft target: Insufficient deceleration for striker function -- round penetrates and stops without detonating
• Grazing impact: Round deflects without sufficient deceleration
• Manufacturing defect: Setback sleeve fails to release
• Base-fuzed duds are often deeply embedded in structures, earthworks, or ground

12. Hazard Warnings

• Base-fuzed UXO found embedded in structures (walls, foundations) is EXTREMELY DANGEROUS -- the fuze has armed and the item may function on any subsequent disturbance
• Do not attempt excavation or extraction of base-fuzed projectiles -- BIP in situ or remote extraction only
• These rounds were designed to penetrate before detonating -- a dud base-fuzed round has penetrated the target and is sitting with the striker mechanism under compression against the impact surface

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DBT

All-Ways Acting Base Fuze with Delay for Concrete-Piercing Rounds

Designation: DBT (ДБТ) Source: METIS/Fenix Insight, BOCN [Rating: B-2]

1. Designation and Variants

2. Physical Description

• Construction: Three-part steel body
  • Short front section screws onto main body
  • Base sealing/setting plate screws into rear
• Location: Base of projectile
• Factory setting: Delay detonation (set at factory, not field-adjustable)

3. Arming Mechanism

• Type: Inertia (setback) AND spin armed
• Dual mechanism: Requires both setback and centrifugal forces from gun firing

4. Function Type

• All-ways-acting: Functions on impact from any angle or orientation
• Delay: Built-in pyrotechnic delay allows penetration of concrete/fortifications before detonation
• Graze: Functions even on oblique impact

5. Arming Distance/Time

• Armed in flight after dual setback/spin arming sequence completes

6. Self-Destruct Feature

• Self-destruct: NO

7. Ordnance Cross-Reference

8. EOD CRITICAL

• All-ways-acting means the fuze will function on impact from ANY direction -- there is no "safe" approach angle
• Concrete-piercing rounds with DBT that fail to detonate are typically buried deep in fortified structures
• BIP ONLY -- the all-ways-acting mechanism, delay element, and inaccessible position make manual RSP impractical and extremely dangerous

9. Hazard Warnings

• 203mm projectiles with DBT fuze contain very large HE charges (up to 12+ kg)
• All-ways-acting: ANY movement of the projectile may cause function
• Delay element condition unknown in UXO -- may be partially initiated

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DBR

Base Detonating Fuze with Auto-Regulated Slowdown

Designation: DBR (ДБР) Source: METIS/Fenix Insight, BOCN [Rating: B-2]

1. Designation and Variants

2. Physical Description

• Type: Base detonating fuze equipped on armor-piercing tracer shells
• Used with: 85mm and 100mm AP-T projectiles

3. Function Type

• Base detonating with auto-regulated delay: The delay duration self-adjusts based on the deceleration profile of the projectile during penetration

4. Ordnance Cross-Reference

5. EOD CRITICAL

• AP-T projectiles with base fuzes: BIP preferred
• Auto-regulated delay means the fuze internal state is unpredictable in a dud -- the regulation mechanism may be in any position

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3. BOMB FUZES

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AVU-ET / AVU-ETM

Standard Russian Universal Aircraft Bomb Fuze

Designation: AVU-ET (АВУ-ЭТ), AVU-ETM (АВУ-ЭТМ) Source: CAT-UXO, Inert Products LLC, Arcon Partners [Rating: A-1 -- manufacturer data and extensive field documentation]

1. Designation and Variants

2. Physical Description

• Weight: 2 kg
• Total length: 210 mm
• Thread part length: 30 mm
• Thread part diameter: 52 mm
• Type: Electro-pyrotechnically armed, mechanically operated
• Installable as: EITHER nose OR tail fuze (universal)

3. Arming Mechanism

• Type: Electro-pyrotechnic arming
• Process: Upon bomb release, an electrical signal from the aircraft fires an arming squib. This ignites a pyrotechnic delay. When the delay burns through, it fires a small propelling charge that pushes the arming plunger, releasing a spring that drives the firing pin housing upward, placing the firing cap in line with the fire train. The fuze is now armed.
• Aircraft interface required: The fuze requires an electrical signal from the aircraft rack/pylon for arming initiation

4. Function Type

Multiple settings available:

5. Arming Distance/Time

Arming times vary by setting:

6. Self-Destruct Feature

• Self-destruct: NO
• "Assault" setting provides 10-14.5 second function delay which may be considered a self-destruct equivalent for low-altitude delivery, but it is a DELAY, not a self-destruct

7. SAFE/ARMED Indicators

• Arming vane (if equipped): Rotation indicates airstream exposure; fixed vane = not armed by wind
• Electrical connector: If the electrical connector shows evidence of activation (burned contacts), the arming squib may have fired
• Setting dial: Shows selected delay setting (M, M3, C3, Assault)
• Pyrotechnic arming is internal -- no positive external armed indicator after squib fires

8. Sensitivity

• Designed for: 76 m/s to terminal velocity impact across full temperature range
• Temperature range: -60C to +150C operational
• Impact sensitivity: Functions on all terrain types in instantaneous mode

9. Ordnance Cross-Reference

10. EOD CRITICAL

AIRCRAFT BOMB UXO IS AMONG THE MOST DANGEROUS ITEMS

• Can it be rendered safe? Fuze removal is the standard RSP for bomb fuzes in accessible wells. Remote fuze removal using approved tools.
• HOWEVER: If the pyrotechnic arming delay has fired but the arming sequence did not complete (partial arm), the fuze is in an EXTREMELY SENSITIVE and unpredictable state.
• "Assault" setting (10-14.5 sec delay): If found as UXO, this delay has expired and the fuze SHOULD have functioned. Its failure to do so indicates a malfunction making the item HIGHLY UNPREDICTABLE.
• BIP threshold: Any evidence of partial function, damage to fuze well, or "Assault" setting = BIP.
• Shelf life: 12.5 years -- fuzes beyond shelf life may have degraded pyrotechnic components

11. Known Failure Modes

• Electrical arming failure: Aircraft electrical signal not received (wiring fault, rack malfunction, jettison vs. release)
• Pyrotechnic delay failure: Arming delay extinguished or not initiated
• Partial arming: Delay burns through but propelling charge fails to move arming plunger fully -- fire train partially aligned
• Low-angle impact: Bomb skips or ricochets; delayed settings prevent immediate function and bomb slides/rolls before delay expires
• Soft ground burial: FAB-series bombs are heavy steel-cased -- they bury deeply on impact, especially in soft soil

12. Hazard Warnings

• FAB-series bombs contain MASSIVE explosive charges (FAB-500: ~200kg HE; FAB-1500: ~675kg HE; FAB-3000: ~1400kg HE)
• Casualty radii are measured in HUNDREDS of meters for larger FAB bombs
• Buried bomb UXO: Bombs may bury 3-6 meters deep in soft soil -- excavation is extremely dangerous
• Dual fuze wells: FAB bombs have BOTH nose and tail fuze wells; BOTH must be assessed even if only one fuze is visible
• A bomb with one functioning fuze and one dud fuze may have partially detonated -- extremely unstable condition

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AVB-E

Russian Nose/Tail Impact Bomb Fuze

Designation: AVB-E (АВБ-Э) Source: BOCN, Bulletpicker [Rating: B-2]

1. Physical Description

• Length: 155 mm
• Diameter: 60 mm (top)
• Type: Electrically activated impact fuze
• Can be used as: Nose or tail fuze

2. Arming Mechanism

• Type: Electrically initiated pyrotechnic arming
• Process: Aircraft electrical charge fires arming squib --> pyrotechnic delay ignites --> propelling charge pushes arming plunger --> spring drives firing pin into armed position --> firing cap aligned and locked
• Armed condition: Irreversible once pyrotechnic sequence begins

3. Function Type

• Point-detonating impact (SQ and delay settings)

4. Ordnance Cross-Reference

• FAB and OFAB series general-purpose bombs
• Used interchangeably with AVU-ET in many applications

5. EOD CRITICAL

• Same hazard profile as AVU-ET
• Irreversible arming: Once the pyrotechnic arming sequence initiates, the fuze cannot be returned to a safe state

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TM-24B

Soviet Mechanical Time Bomb Fuze

Designation: TM-24B (TM-24Б) Source: Ordnance.com, CAT-UXO, Bulletpicker [Rating: B-2]

1. Designation and Variants

2. Physical Description

• Type: Mechanical time fuze for aircraft bombs
• Mounting: Nose OR tail fuze well
• Visible feature: Time setting mechanism on fuze body

3. Arming Mechanism

• Type: Mechanical clockwork initiated at release
• Process: Upon bomb separation from aircraft, the clockwork mechanism begins running. After preset delay, the fuze fires.

4. Function Type

• Time delay only: Detonates after preset mechanical time delay
• No impact function -- this is a pure time fuze
• Multi-time: Multiple delay settings available

5. Ordnance Cross-Reference

6. EOD CRITICAL

TIME-FUZED BOMB UXO IS EXTREMELY DANGEROUS

• If the bomb has not detonated but was released from an aircraft: The clockwork has been running. Either:
  • (a) The clockwork ran to completion and the fuze failed to fire -- MECHANICAL FAILURE, unpredictable state
  • (b) The clockwork is still running (unlikely if significant time has passed)
  • (c) The clockwork mechanism jammed
• In ALL cases: BIP. Do not approach time-fuzed bomb UXO.
• TM-24B was used with incendiary and chemical bombs -- additional HAZMAT considerations

7. Hazard Warnings

• Chemical weapons consideration: KhAB-200 is a chemical bomb -- if found with TM-24B fuze, CBRN protocols apply
• Incendiary bombs (ZAB series): Contain thermite or white phosphorus -- additional fire hazard on BIP
• Clockwork mechanisms can jam and then restart -- a time-fuzed item that appears to be a dud may spontaneously detonate

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4. GRENADE FUZES

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UZRGM / UZRGM-2

Universal Russian Hand Grenade Fuze -- The Most Widely Produced Grenade Fuze in History

Designation: UZRGM (УЗРГМ), UZRGM-2 (УЗРГМ-2), UZRGM-IM (УЗРГМ-ИМ) Source: Wikipedia, Fenix Insight/METIS, Bulletpicker, CAT-UXO [Rating: A-1 -- universally documented]

1. Designation and Variants

2. Physical Description

• Weight: 51 g
• Length: 99-104 mm
• Construction: Tubular steel body housing the delay element and detonator
• External features: Safety lever (spoon), safety pin with ring pull, cylindrical body
• Seven main components: Main body; ring-pull safety pin; safety lever (spoon); striker assembly (spring-loaded); igniter; delay element; flash/noise charge (detonator)

3. Arming Mechanism

• Type: Striker-release (spring-loaded striker)
• Process:
  1. Safety pin holds safety lever in place, compressing the striker spring
  2. Grenade is gripped with lever held against body
  3. Pin is pulled -- lever is now held only by thrower's hand grip
  4. Upon release (throw), the safety lever flies off
  5. Striker is released, driven by spring into the primer/igniter
  6. Igniter fires, initiating the pyrotechnic delay element
  7. Delay element burns for 3.2-4.2 seconds
  8. Delay fires the detonator, detonating the grenade main charge
• Identical in principle to US M213/M228 grenade fuze family

4. Function Type

• Pyrotechnic delay: 3.2 to 4.2 seconds (nominal 3.5 sec)
• NO impact function -- purely time-delay
• Detonation occurs after delay regardless of whether grenade has impacted

5. Arming Distance/Time

• Arming is IMMEDIATE upon lever release -- the delay begins burning the instant the lever flies off
• There is no minimum arming distance or delay-to-arm -- the fuze is armed the instant the lever releases

6. Self-Destruct Feature

• The delay element IS the self-destruct -- the grenade will detonate 3.2-4.2 seconds after lever release regardless of conditions
• However: If the delay element fails to burn through, the grenade becomes a dud with the striker mechanism fired and the igniter/delay in an unknown state

7. SAFE/ARMED Indicators

• SAFE indicators:
  • Safety pin IN place (ring and pin visible, cotter pin legs spread)
  • Safety lever (spoon) IN place and held by pin
  • Striker NOT released (lever intact)
• ARMED indicators:
  • Safety pin REMOVED
  • Safety lever MISSING (has flown off)
  • These two conditions = FUZE IS INITIATED, delay is burning or has burned
• DUD indicators:
  • Safety pin removed, lever missing, grenade intact (not detonated) = DUD with initiated delay element

8. Sensitivity

• Pull force for pin: Moderate -- designed for one-hand extraction with ring pull
• Striker spring force: Sufficient to reliably fire the primer
• The fuze itself is NOT impact-sensitive -- however, a dud grenade with a partially burned delay element may be sensitive to shock

9. Ordnance Cross-Reference

10. EOD CRITICAL

• Dud grenade (pin out, lever gone, intact): The delay element has been initiated. It may have:
  • (a) Burned through completely but the detonator failed -- detonator is in a SENSITIZED state
  • (b) Partially burned and extinguished -- delay element may re-ignite on disturbance
  • (c) Igniter failed to fire delay element -- but striker has impacted primer, which may have generated heat/spark without sustained ignition
• RSP approach: BIP ONLY for dud grenades. Do not handle, kick, or throw.
• Intact grenades (pin in, lever on): Can be rendered safe by verifying pin security. However, corroded or damaged pins may not hold -- handle with extreme care.
• If pin is PARTIALLY removed (pin bent, partially extracted): TREAT AS ARMED. BIP.

11. Known Failure Modes

• Delay element moisture: Moisture ingress (especially in aged grenades) causes delay element to extinguish
• Primer failure: Striker impacts primer but primer fails to fire
• Delay composition degradation: Aged delay elements may burn at unpredictable rates -- faster (premature) or slower than designed
• Manufacturing defects: Poor delay element compression or composition

12. Hazard Warnings

• UBIQUITOUS -- UZRGM-series fuzes are found in virtually every conflict zone worldwide
• Simplicity means reliability -- dud rate is historically LOW for this fuze; finding a dud suggests significant anomaly
• Aged grenades (30+ years): Pyrotechnic delay and detonator may have degraded, making function unpredictable
• Corroded safety pins: May fail to retain the lever -- a corroded grenade may self-arm if the pin breaks
• Improvised use: UZRGM fuzes are commonly removed from grenades and used as improvised fuzing for IEDs, booby traps, and improvised munitions -- be alert for UZRGM fuzes attached to non-standard items

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VMG-K

Impact Fuze for VOG-25 (40mm) Grenades

Designation: VMG-K (ВМГ-К) Source: Arcus JSC, Kintex, Armaco, CAT-UXO [Rating: A-1]

1. Physical Description

• Type: Mechanical, nose, point-detonating fuze with SQ action
• Features: Distant arming and self-destruction
• Fits: VOG-25 and 40x46mm HE grenades

2. Arming Mechanism

• Type: Distant arming (setback + centrifugal/inertial safety)
• Arming distance: 10 to 40 m from muzzle
• Unarmed zone: First 10-40 m -- grenade will not detonate on impact within this zone

3. Function Type

• Super-quick (SQ): Instantaneous detonation on impact
• Functions on: Solid ground, marshy ground, snow

4. Self-Destruct Feature

• YES: Self-destruct at 14 to 19 seconds after firing if no impact occurs
• This is a critical safety feature preventing armed grenades from persisting as UXO

5. Ordnance Cross-Reference

6. EOD CRITICAL

• VOG-25 specifications: 103mm long, 250g total weight, 48g explosive charge
• Self-destruct SHOULD fire at 14-19 sec -- if found as UXO, self-destruct has FAILED
• Dud VOG-25: Armed impact fuze + failed self-destruct = handle as armed, sensitive munition
• Small size: May be overlooked in vegetation or rubble
• RSP: BIP preferred; these are small and inexpensive to destroy

7. Hazard Warnings

• Small casualty radius (~5-7m) but lethal within it
• Dud grenades on the surface are trip/step hazards -- armed fuze may function on minimal disturbance
• The 10-40m arming distance means duds found close to launch point are likely UNARMED -- but do not rely on this assumption

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VMG-M-L

Impact Fuze for VOG-17 (30mm) Grenades

Designation: VMG-M-L (ВМГ-М-Л), VMG-M (ВМГ-М) Source: Arcus JSC, Kintex [Rating: A-1]

1. Physical Description

• Type: Mechanical, nose, point-detonating fuze with SQ action
• Features: Distant arming and self-destruction

2. Arming Mechanism

• Arming distance: 10 to 60 m from muzzle

3. Function Type

• Super-quick (SQ): Instantaneous on impact

4. Self-Destruct Feature

• YES: Self-destruct at 25-36 seconds (VMG-M: 25 sec; VMG-M-L: 28-36 sec)

5. Ordnance Cross-Reference

6. EOD CRITICAL

• AGS-17 fires at high rate -- multiple dud grenades may be found in clusters
• Same hazard profile as VMG-K but higher volume of items likely
• BIP preferred -- consolidate and destroy

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5. MINE FUZES

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MV-5

Pressure-Operated Mine Fuze

Designation: MV-5 (МВ-5) Source: METIS/Fenix Insight, CAT-UXO [Rating: B-2]

1. Physical Description

• Type: Relatively simple, pressure-operated mine fuze
• Construction: Mechanical pressure-activated firing mechanism

2. Arming Mechanism

• Type: Direct pressure on plunger
• CRITICAL: The MV-5 has NO safety devices
• The fuze is armed as installed -- there is no arming delay, no safety pin beyond the installation configuration

3. Function Type

• Instantaneous on pressure application -- direct mechanical firing

4. Self-Destruct Feature

• Self-destruct: NO

5. Ordnance Cross-Reference

• Various Soviet anti-tank and anti-personnel mines
• May also be used in booby trap configurations

6. EOD CRITICAL

WARNING: NO SAFETY DEVICES

• The MV-5 has NO safety mechanisms -- it is in a ready-to-fire state whenever installed
• RSP: Mine clearance procedures; probe, locate, and EITHER:
  • Remove pressure carefully and extract fuze (if accessible and not booby-trapped)
  • BIP in place
• Booby trap warning: The simplicity of the MV-5 makes it ideal for improvised booby traps -- ALWAYS check for anti-handling devices beneath the mine

7. Hazard Warnings

• NO SAFETY = NO MARGIN FOR ERROR
• Pressure threshold is the ONLY thing preventing function -- any force on the pressure plate exceeding the threshold will initiate
• Corrosion may reduce or INCREASE trigger sensitivity over time

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MVE-72

Electronic Breakwire/Tripwire Firing Device

Designation: MVE-72 (МВЭ-72) Source: METIS/Fenix Insight, Security Training Posters, GICHD [Rating: B-2]

1. Physical Description

• Type: Battery-powered electronic firing device using breakwire trigger
• Introduced: ~1972 by Soviet Union
• Operation: Uses a loop of break wire (tripwire) as a collapsing circuit; when the wire breaks, the circuit changes state and fires the detonator

2. Arming Mechanism

• Type: Electronic -- armed when battery is connected and breakwire loop is intact
• Arming process: Install battery, connect breakwire, extend wire -- device is now armed
• Delay to arm: May incorporate electronic delay after battery connection

3. Function Type

• Tripwire (breakwire) initiated
• Electronic firing: Clean, reliable electrical initiation of detonator

4. Self-Destruct Feature

• Self-destruct: Battery depletion eventually renders the device inert -- but this may take weeks to months depending on battery condition

5. Ordnance Cross-Reference

• OZM-72 bounding AP mine
• MON-50 directional AP mine
• MON-90 directional AP mine
• Various demolition charges
• Booby trap configurations

6. EOD CRITICAL

• Electronic firing device -- may be sensitive to electromagnetic interference (EMI)
• Breakwire principle: The wire MUST remain intact for the device to remain in standby. If the wire is already broken, the device has either:
  • (a) Fired successfully and the mine detonated
  • (b) Fired but the detonator/mine failed -- ARMED ELECTRONIC CIRCUIT with fired detonator
  • (c) Battery was dead when wire broke -- may or may not be safe
• RSP: Identify the breakwire. Do NOT cut the breakwire (cutting = breaking = firing signal). Disable by disconnecting the battery or detonator circuit.
• If breakwire is already broken: Treat as potentially armed; battery may still have charge

7. Hazard Warnings

• Breakwire may be extremely thin and hard to see -- invisible in vegetation
• Electronic devices may be susceptible to RF interference -- radio transmissions near the device could theoretically cause firing
• Maintain radio silence around suspected MVE-72 devices until the device is identified and battery status assessed

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MUV Series

Universal Pull/Push Mine Fuzes -- The Most Common Soviet Mine Fuze Family

Designation: MUV (МУВ), MUV-2 (МУВ-2), MUV-3 (МУВ-3), MUV-4 (МУВ-4) MUV = Модернизированный Упрощённый Взрыватель = "Modernized Simplified Fuze" Source: Bulletpicker, METIS/Fenix Insight, CAT-UXO, Boobytrap Recognition Manual [Rating: A-1]

1. Designation and Variants

2. Physical Description

• Type: Small, simple, mechanical pull/push firing device
• Construction: Steel or brass body, spring-loaded striker, retaining pin
• Key components: Body, striker, striker spring, retaining pin (pull wire or pressure cap attachment point), detonator well (accepts MD-2/MD-5M detonator)

3. Arming Mechanism

• MUV: Instantaneous -- armed when retaining pin is installed and under tension from tripwire or pressure plate. Remove pin = striker fires.
• MUV-2: Incorporates an arming delay device -- after installation, a lead element holds the striker. Over several minutes, the lead element deforms under spring pressure, and the fuze becomes fully armed. This gives troops time to lay and camouflage the mine.
• MUV-3: Similar delay mechanism to MUV-2, with additional retaining clip
• MUV-4: Timed delay-to-arm mechanism

4. Function Type

• Pull: Tripwire attached to retaining pin; pulling the pin releases the striker
• Push: Pressure applied to a cap/plate pushes the striker retaining mechanism out of engagement
• Instantaneous: No delay between pin release and striker firing (except arming delay on MUV-2/3/4)

5. Self-Destruct Feature

• Self-destruct: NO
• These fuzes remain armed indefinitely until the striker is released or the spring degrades

6. Ordnance Cross-Reference

7. EOD CRITICAL

THE MOST COMMONLY ENCOUNTERED MINE FUZE IN THE WORLD

• Can it be rendered safe? YES, if the fuze type and configuration can be positively identified AND there are no anti-handling devices.
• RSP approach:
  • Identify the fuze variant and function mode (pull or push)
  • Identify the tripwire/pressure plate connection
  • For PULL function: Do NOT cut the tripwire (cutting may cause the wire to pull). Secure the striker retaining pin in place, then disconnect the wire.
  • For PUSH function: Remove pressure carefully, verify striker pin is retained
  • Extract fuze from detonator well
• HOWEVER: The MUV-2/3 arming delay means that a recently placed mine may not yet be armed -- OR it may arm while you are working on it.
• Anti-handling: MUV fuzes are frequently used with anti-lift devices beneath mines. ALWAYS assume an anti-handling device is present until proven otherwise.

8. Hazard Warnings

• GLOBAL HAZARD: MUV-fuzed mines are found on every continent where Soviet weapons were supplied
• Longevity: These fuzes remain functional for DECADES in the ground. Mines from the 1940s have killed people in the 2020s.
• Improvised use: MUV fuzes are used extensively in IEDs and booby traps -- they are simple, reliable, and widely available
• Corrosion: Corroded retaining pins may fail spontaneously, causing the mine to self-arm and fire
• Lead delay element (MUV-2): Temperature-dependent -- hot weather shortens arming delay; cold weather lengthens it. In very cold conditions, the mine may not arm at all... but may arm later when temperature rises.

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VP-13

Seismic/Electronic Sensor Mine Firing Device

Designation: VP-13 (ВП-13) Source: METIS/Fenix Insight, Security Training Posters, CAT-UXO [Rating: B-2]

1. Physical Description

• Diameter: 15.5 cm
• Height: 36 cm
• Weight: 4.2 kg
• Power: Six R20 cells (D-cell batteries)
• Components: SV-20P geophone, wire spool, MUV-4 delay-to-arming fuze, NM fuze in 200g TNT demolition block (self-destruct charge)

2. Arming Mechanism

• Type: Electronic with seismic (geophone) sensor
• Process: MUV-4 provides delay-to-arming after installation; once armed, the geophone listens for ground vibrations
• Detection radius: 15 m radius for footstep detection
• Target discrimination: Electronic circuit analyzes vibration pattern to identify footsteps vs. other vibrations

3. Function Type

• Seismic-triggered: Geophone detects ground vibrations; if identified as footsteps, sends firing impulse to connected mine
• Can control up to 5 mines via wire connection
• Selective firing: Fires mines sequentially (first detection fires mine #1, etc.)

4. Self-Destruct Feature

• YES: 200g TNT self-destruct charge detonates at end of battery life
• Battery life: Approximately 69 days
• Self-destruct mechanism: NM fuze in TNT block fires when battery voltage drops below threshold

5. Ordnance Cross-Reference

• Controls various mines (AP and AT) via wire connections
• Used in mixed minefields with OZM-72, MON-50, MON-90, etc.

6. EOD CRITICAL

ELECTRONIC SENSOR DEVICE -- EXTREME CAUTION

• The VP-13 can detect approaching personnel at 15m -- approaching the device may trigger connected mines
• Multiple mines may be connected -- clearing one mine does not clear the system
• Self-destruct charge (200g TNT): If battery is near end of life, self-destruct may fire at any time
• RSP approach:
  • Locate device from maximum distance (electronic detection, visual search)
  • Trace all connecting wires to identify all controlled mines
  • Disable by cutting firing wires to mines (at maximum distance from mines, not from the VP-13)
  • The VP-13 itself contains a 200g TNT self-destruct -- treat as an explosive device
  • Battery condition unknown -- may self-destruct at any time
• BIP preferred if connected mines cannot be positively identified and traced

7. Hazard Warnings

• APPROACH HAZARD: Walking toward a VP-13 at less than 15m may trigger it
• 69-day battery life means devices deployed more than ~2 months ago have likely self-destructed -- but battery life varies with temperature and battery quality
• Self-destruct scatter: 200g TNT detonation will scatter the device components and may scatter secondary hazards (wire, mine components)
• Wire connections may be buried -- follow wires carefully before cutting
• In cold weather, battery life may be significantly shorter -- self-destruct may occur earlier than 69 days

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6. MISSILE/ROCKET FUZES

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MRV / MRV-U

Standard Fuzes for 122mm Grad Rockets

Designation: MRV (Index 9E210), MRV-U (Index 9E244) Source: Arcus JSC, Armaco JSC, Missilery.info, GICHD, CAT-UXO [Rating: A-1]

1. Designation and Variants

2. Physical Description

• Type: Mechanical, nose, point-detonating fuze with selectable SQ/delay
• Location: Nose of the rocket warhead
• Visual: Large nose-mounted fuze with setting ring; larger than artillery fuzes due to rocket warhead diameter

3. Arming Mechanism

• Type: Setback armed (armed after propellant burns and rocket accelerates)
• Distant arming: Fuze arms in flight, typically 150-400 m after launch
• Mechanism: Setback forces from rocket motor acceleration release the safety/arming device

4. Function Type

Three selectable settings (MRV-U):

5. Arming Distance/Time

• Arming distance: 150-400 m after launch (varies by specific variant and rocket motor)
• Armed by: Rocket motor acceleration (setback)

6. Self-Destruct Feature

• Self-destruct: NO
• Rocket motor burnout does not affect fuze -- fuze remains armed after motor burns out

7. SAFE/ARMED Indicators

• Setting ring position: Shows O, M, or Б
• No positive external armed/safe indicator
• If rocket has impacted and not detonated: Assume armed

8. Sensitivity

• Designed for: Terminal velocities of 100-500+ m/s depending on range
• Functions on all terrain types in SQ mode
• Short/long delay: Allows ground penetration before detonation

9. Ordnance Cross-Reference

10. EOD CRITICAL

• Grad rocket UXO is EXTREMELY COMMON in current conflicts
• Rocket motor may still contain propellant -- fire/burn hazard in addition to explosive warhead
• RSP: Remote fuze removal is possible if rocket is intact and stable
• BIP: Preferred for damaged rockets, rockets embedded in structures, or any uncertainty about fuze status
• Arming distance note: Rockets that impact within 150-400m of the launcher may be UNARMED -- but do not rely on this; treat all as armed

11. Known Failure Modes

• Impact on soft ground at steep angle: Rocket buries without sufficient deceleration for the striker
• Motor failure/partial burn: Rocket may land short with low velocity, insufficient for fuze function but fuze may still be armed
• Dud rockets with intact motors: Fire/explosive hazard from remaining propellant
• Fin damage: Rockets that lose fins in flight may impact in unpredictable orientation

12. Hazard Warnings

• VOLUME: BM-21 fires 40 rockets in a salvo; a full battalion fires hundreds. A single engagement can produce dozens of dud rockets across the target area.
• Rocket motors: Contain solid propellant -- risk of burn/cook-off if exposed to fire
• Warhead fragmentation: 9N51 warhead produces ~3,920 fragments -- massive casualty radius
• Multiple fuze settings may be mixed in a salvo -- different rockets may be set to different delay modes

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9E244 (Uragan)

Fuze for 220mm Uragan Rockets

Designation: MRV-U (9E244) used in Uragan system Source: Wikipedia (BM-27 Uragan), ARES, GlobalSecurity [Rating: B-1]

1. Ordnance Cross-Reference

2. Key Details

• 9M27F HE-FRAG warhead uses MRV-U (9E244) fuze -- same fuze family as Grad but for 220mm rocket
• 9M27K cargo warheads use expulsion/time fuzes (similar to T-90 function) for submunition dispensing
• Submunitions from 9M27K use 9E246/9E246M fuzes (see submunition fuze section above)

3. EOD CRITICAL

• 220mm rockets are MUCH larger than 122mm Grad rockets -- warhead contains 51.9 kg HE for the HE-FRAG variant
• Cargo variants dispense submunitions -- if the rocket failed to open, the ENTIRE cargo of 24-30 submunitions is contained in an intact warhead (EXTREME hazard)
• BIP ONLY for intact cargo warheads -- catastrophic failure risk on any handling

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Smerch Rocket Fuzes

Fuzes for 300mm Smerch System

Designation: Various fuzes for 9M55-series rockets Source: Wikipedia (BM-30 Smerch), ARES, GlobalSecurity, Army Technology [Rating: B-2]

1. Rocket Variants and Fuzing

2. EOD CRITICAL

• 300mm rockets are the largest MLRS munitions in Russian service -- massive explosive content
• 9M55K cargo rocket: Contains 72 x 9N235 submunitions, each with 9E272 impact fuze and 110-second self-destruct. A single rocket dud or failed-to-open cargo warhead contains 72 armed submunitions.
• 9M55K1 Motiv-3M: Sensor-fuzed top-attack submunitions are self-forging fragment (EFP) warheads with millimeter-wave radar sensors -- EXTREMELY dangerous as UXO. Sensor may still be active. BIP ONLY.
• 9M55C thermobaric: If the fuel-air explosive warhead fails to function, the dispersed fuel cloud may still be present -- vapor explosion hazard. Evacuate area. BIP from maximum distance.
• Rocket dimensions: ~7.5m long, 800+ kg -- these are essentially short-range ballistic missiles

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7. CROSS-REFERENCE MATRIX

Fuze-to-Ordnance Quick Reference

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8. EOD DECISION FRAMEWORK

Quick-Reference RSP Decision Tree

IDENTIFY FUZE TYPE
    |
    +-- Is it a PROXIMITY fuze (AR-5, AR-139, 9E156)?
    |       |
    |       YES --> DO NOT APPROACH with metal. Remote BIP.
    |               RF silence within hazard zone.
    |
    +-- Is it a SUBMUNITION fuze (9E246, 9E272)?
    |       |
    |       YES --> BIP ONLY. Never handle. Remote consolidation only.
    |
    +-- Is it a TIME fuze (T-7, T-90, TM-24B)?
    |       |
    |       YES --> BIP PREFERRED. Internal pyro state unknown.
    |               If T-7 in SQ mode: treat as PD fuze.
    |
    +-- Is it a MINE fuze (MV-5, MVE-72, MUV, VP-13)?
    |       |
    |       YES --> Mine clearance protocols.
    |               Check for anti-handling devices FIRST.
    |               VP-13: Do not approach within 15m (geophone range).
    |
    +-- Is it a BOMB fuze (AVU-ET, AVB-E, TM-24B)?
    |       |
    |       YES --> Assess both fuze wells. Remote fuze removal if
    |               stable and no partial function. BIP for any doubt.
    |               FAB-1500/3000: MASSIVE evacuation radius.
    |
    +-- Is it a PD fuze (V-429, RGM-2, M-6, GVMZ)?
    |       |
    |       YES --> Assess stability. Evidence of partial function?
    |               |
    |               NO partial function --> Remote fuze removal possible
    |               YES partial function --> BIP
    |               ANY doubt --> BIP
    |
    +-- Is it a BASE fuze (MD-5, DBT, DBR)?
            |
            YES --> Fuze is NOT accessible. BIP.
                    All-ways-acting (DBT): ANY movement may cause function.

Critical Thresholds Summary

Dud Rate Estimates

Estimate: Russian/Soviet ordnance fuze dud rates vary significantly by type and age: Based on: Manufacturer claims vs. field observation data from multiple conflicts Supporting evidence: GICHD Ukraine Guide (A-2), HRW Cluster Munitions reports (B-1), ARES documentation (B-1) Caveats: Field-observed rates subject to survivorship bias; manufacturer test conditions do not reflect combat conditions

NOTE ON SUBMUNITION DUD RATES: The 10-30% field-observed dud rate for submunitions is THE critical planning factor for post-conflict clearance. A single Smerch 9M55K cargo rocket dispersing 72 submunitions at a 20% dud rate leaves ~14 armed submunitions on the ground. A full battery salvo of 12 rockets leaves ~170 armed submunitions.

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Sources

Primary Technical Sources (Rating A)

• Arcus JSC - V-429 Fuze
• Arcus JSC - RGM-2 Fuze
• Arcus JSC - AR-139 Proximity Fuze
• Arcus JSC - VMG-K Fuze
• Arcus JSC - VMG-M-L Fuze
• Arcus JSC - MRV-U Fuze
• Arcus JSC - M-6 Fuze
• Romarm - V-429 Datasheet (PDF)
• Arcon Partners - AVU-ETM

Technical Databases (Rating B)

• CAT-UXO - V-429 Fuze
• CAT-UXO - RGM-2 Fuze
• CAT-UXO - UZRGM Fuze
• CAT-UXO - MRV-U Fuze
• METIS/Fenix Insight - Fuze Database
• Fenix Insight - UZRGM
• Fenix Insight - 9E246
• Fenix Insight - 9E272
• Fenix Insight - 9E156

Handbooks and Manuals (Rating A-B)

• Russian Fuze Handbook (Bulletpicker)
• Fuzes Handbook Part 1 (Bulletpicker)
• GICHD Explosive Ordnance Guide for Ukraine 2022
• Boobytrap Recognition Manual Vol. 4 - USSR/Russian
• Soviet Mine Warfare Equipment (TM-5-223A)

Conflict Documentation (Rating B)

• ARES - 9N210 Submunitions in Ukraine
• ARES - 9N235 Submunitions in Ukraine
• ARES - 9M55K and 9N235 in Ukraine
• NCT CBNW - Russian Submunitions in Ukraine

Policy and Analysis (Rating B-C)

• HRW - Cluster Munition Myths and Realities (PDF)
• NIDS - Reliability of Cluster Munitions (PDF)
• Wikipedia - BM-21 Grad
• Wikipedia - BM-27 Uragan
• Wikipedia - BM-30 Smerch