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|  MIL-C-63990C (AR)
REQUIREMENTS
3.
3.1 Cartridge. The cartridge shall comply with all
requirements specified on drawing 9342865, all associated
drawings and with all requirements specified in applicable
specifications and standards.
3.2 Component parts and materials. Component parts and
materials shall be in accordance with the applicable drawings and
specifications.
3.3 Bullet extraction. The force required to extract the
bullet from the cartridge case shall not be less than 45 pounds.
3.4 Residual stress. The cartridge case shall not split
when subjected to a 1 percent mercurous nitrate solution for 15
minutes.
The cartridge shall not release more
3.5 Waterproofness.
than one bubble of air when subjected to a positive internal
pressure of 7.5 pounds per square inch (psi) for 30 seconds
minimum.
3.6 Velocity. The average velocity of the cartridges,
conditioned at 70 2F, shall be 2,990 feet per second (fps)
40 fps at 78 feet from the muzzle of the weapon. The standard
deviation of the velocities shall not exceed 40 fps.
3.7 Chamber pressure. The average chamber pressure of the
sample cartridges, conditioned at 70 2F shall not exceed
55,000 psi. 55,000 psi. Neither the chamber pressure of an individual
test cartridge nor the average chamber pressure plus three
standard deviations of chamber pressure shall exceed 61,000 psi.
3.8 Port Pressure. The mean port pressure minus three
standard deviations shall not be less than 12,700 psi for sample
cartridges conditioned to 70 2F.
3.9 Trace test.
3.9.1 Night test. The bullet of the tracer cartridge shall
exhibit a trace below full luminosity and preferably invisible
from the muzzle of the weapon for a range of at least 43 feet
(14.3 yards, 13 meters). Visible trace of full luminosity shall
begin at a range not greater than 230 (76.7 yards, 70 meters)
feet from the muzzle of the weapon and shall continue to a
minimum range of 2,950 feet (983.3 yards, 900 meters) .
4
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