APPENDIX "F" (CONT'D)
50.3 Upon completion of firing, all cartridge cases from the test ammunition shall be
carefully examined for firing defects. If any defect is found, a detailed check of the equipment
shall be made to determine whether the ammunition or the equipment is at fault. If it is
established that a faulty weapon is responsible for the firing defect, than the test shall be
disregarded, the weapon shall be corrected or replaced and the tests with that one weapon shall
be refired. If it cannot be established that the weapon or other equipment is at fault, then the
firing defects shall be charged against the ammunition.
60.1 Misfire. Failure of a round or ammunition to fire after the initiation impulse has bee
applied to the primer.
a. The primer fails to fire when struck by the firing pin.
b. The propellant does not ignite when the primer fires normally.
60.2 Hangfire. Any delay in the functioning of a cartridge after the initiating impulse has
been applied to the primer.
60.3 Pierced primer. A pierced primer is one in which the primer cup is entirely perforated
by the firing pin. It can be identified by a visible hole through the primer, or if the perforation be
minute, by discoloration of the firing pin indent caused by burning gas. This casualty may be
caused by an imperfect firing pin or by one of improper contour; or it may be caused by the metal
in the base of the primer cup being too thin, or too soft, or defective from lamination, scale etc.
60.4 Primer leak. Discoloration caused by gas leakage around the junction between the
primer cup and the primer pocket wall.
60.5 Loose primer. Looseness which permits the fired primer to fall from the primer pocket
after the cartridge is fired, without distortion to the primer pocket.
60.6 Blown primer. A blown primer is a primer which,m when the cartridge is fired, is
separated completely from the head of the cartridges case, and both the head of the case and
pocket are enlarged and deformed. This condition results from a soft head.
60.7 Flow-back. A flow-back may be described as the distortion al foxing of the dome of
the primer cup in the the space between the firing pin and the firing pin hole in the bolt face.
60.8 Punch-out. A punch-out is the removal of metal in the dome of the primer.
60.9 Primer setback. The backward movement of a primer cup in the cartridge case which
occurs when the base of the cup is not properly supported by the bolt face, and protrudes above
the head of the cartridge case.
60.10 Ruptured case. Circumferential separation of the case wall produced by firing.
Ruptures are divided into two categories, partial and complete. A partial rupture is one which