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| MIL-C-60872A
4.7.5 Airtightness. Each cartridge shall be subjected to specified pressure differential. The method for
determining airtightness shall be with a helium mass spectrometer. The helium leak rate shall be converted
to standard cubic inches air. Failure to comply with the requirements of 3.5.2 shall be cause for rejection of
the cartridge.
4.7.6 Sealant application. Five cartridges for first article inspection shall be disassembled in such a
manner that determination can be made that the sealant has been properly applied for the full length of the
joining surfaces at the junction of the sealing disc and case sidewall and that the propellant cavity is free of
sealant.
4.7.7 Vibration test. Twelve of the 21 assembled cartridges of the first article sample, x-rayed as directed
in 4.7.4, properly identified, shall be subjected to vibration. The method and procedures for performing the
vibration test shall be in accordance with MIL-STD-810, Method 514.3, Test Procedure I, Test Condition
I-3.2.5 (see 6.2). Then the 12 vibrated cartridges shall be x-rayed again. Evidence of any disintegration of the
primer, propellant, or igniter, or derangement of any component shall be cause for rejection of the sample.
4.7.8 Functional. The following tests shall be performed by the Government.
4.7.8.1 Primer sensitivity. A quantity of cartridges, in accordance with table II, void of delay charge
igniter and propellant, from the first article sample and each subsequent lot shall be tested for sensitivity. In
the event loaded cartridges are selected for test, remove and discard all powder charges from the test cartridge
by sectioning the cartridge case around the periphery, inch maximum above the base. Drop test at 13 inches
(adjusted) using a steel ball 15/16-inch in diameter, weighing 1.94 0.02 ounces, in a primer sensitivity
machine with a cartridge holder approved by the acquiring agency. The height of 13 inches shall be adjusted
taking into consideration the actual weight of the ball so that the energy level specified in 3.6.1 is achieved.
Failure of the sample to comply with the requirements of 3.6.1 shall be cause for rejection of the sample or
the lot.
4.7.8.2 Ballistics.
4.7.8.2.1 First article. Twenty-one cartridges of the first article sample shall be grouped and temperature
conditioned as described in table III and 4.8. Following removal from the conditioning chamber, the cartridge
shall be tested as required by 3.6.2.2. Failure of a cartridge to comply with the requirements of 3.6.2.2 shall
be cause for sample rejection.
4.7.8.2.2 Production lot acceptance. Twenty-one assembled cartridges from each production lot shall
be divided into three equal groups, temperature conditioned, and fired in accordance with 3.6.2.2. If the
sample is not evenly divisible by three, the remaining cartridges will be tested at -60 and
205 F. Failure of a cartridge to comply with 3.6.2.2 shall be cause for rejection of the lot. In addition to the
sample of cartridges for the above test, 10 additional cartridges shall be furnished from each production lot
for investigative purposes.
4.7.8.3 Retest. There shall be no retests.
4.7.8.3.1 Test failure. If a test failure is attributable to an assignable cause, excluding the test cartridge,
the original test results shall be discarded and that test reconducted.
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