MIL-PRF-71139A
3.5 Operating requirements.
3.5.1 Chamber pressure. The average plus 3.0 standard deviations of chamber pressure shall not
exceed 454 MPa when the cartridge is conditioned at 21oC. The average plus 2.0 standard deviations shall
not exceed 496 MPa when the cartridge is conditioned at -46o and 63oC. No individual value shall exceed
496 MPa during any testing.
3.5.2 Action time. The action time of the cartridge shall not exceed 6.0 milliseconds.
3.5.3 Function, casualty and metal parts security. The cartridge shall function without casualty
while maintaining metal parts security. Cartridges and subcomponent parts shall exhibit integrity during
weapon cycling, chambering, firing, and in ballistic flight.
3.5.4 Dispersion. The standard deviation of projectile impacts in both the horizontal and the
vertical directions shall be no greater than 0.77 mils when fired from a Mann barrel and no greater than
0.87 mils when fired at a rate of 100 shots per minute (spm) from a M242 autogun.
3.5.5 Trajectory. The cartridge shall have a projectile trajectory within 10% of the trajectory
identified for the M792 in FT25-A-2 throughout a range of 3000 meters.
3.5.5.1 Muzzle velocity. The average muzzle velocity of the projectile minus 2.0 standard
deviations shall be no less than the minimum allowed velocity to achieve the trajectory match
requirement when the cartridge is conditioned at 21oC and the velocity standard deviation of the sample
shall not exceed 13 meters per second.
3.5.6 Surface danger zone. The cartridge shall comply with the M792 surface danger zone stated
in DA PAM 385-63 (see 6.19).
3.5.7 Projectile trace. The projectile shall provide a continuous visible trace (both thermal and
spectral) from the muzzle of the weapon to a range of at least 2000 meters when viewed through the
Bradley Fighting System (BFVS) Integrated Sight Unit (ISU) or IBAS.
3.5.8 Projectile non-arming. The projectile shall not function upon impact with a 0.063 inch
nominal thickness 2024-T3 aluminum plate at 0o + 10o obliquity at a distance from the muzzle of the
weapon of no less than the safe separation distance of the detonated projectile.
3.5.9 Projectile impact function. The projectile shall function upon impact with a 0.063 inch
nominal thickness 2024-T3 aluminum plate at 0o + 10o obliquity, at a distance of 200 meters from the
muzzle.
3.5.10 Projectile self-destruct function. The projectile shall self destruct after 3000 meters of free
flight.
3.5.11 Smoke. Any smoke produced from firing the M792 shall not impede the shooter's vision
from the gun position after firing a 10-round burst from the M242 autogun.
3.5.12 Flash. The cartridge shall not exhibit any secondary muzzle flash that exceeds the
following: a brightness of 6,000 candles or a duration of 3 milliseconds. The cartridge shall not exhibit
any breech flash.
3.5.13 Cook off. The cartridge shall not cook off when left chambered in a hot gun tube for 30
minutes.
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