MIL-C-46409D (AR)
APPENDIX "D"
CHAMBER PRESSURE TEST PROCEDURE
10.0 PURPOSE
The Chamber-Pressure test is precisely controlled test to determine the chamber-pressure
exerted, expressed in pounds per-square inch in the chamber of the gun. The test is performed as
a safety measure to insure that the pressure developed by the ammunition is safe for firing in the
weapon for which it is intended.
20.0 EQUIPMENT
20.1 Equipment listed in the Chamber-pressure section of the appropriate Inspection
Equipment List shall be used.
20.2 The firing range shall be arranged as shown in figure D-1.
20.3 Pier or mount of solid construction on which test fixture assembly shall be mounted.
30.0 USE OF STANDARD (REFERENCE) CARTRIDGES
30.1 Standard (reference) cartridges shall be used to establish range and equipment
corrections prior to firing an ammunition lot for acceptance. One standard (reference cartridge
shall be fired for each cartridge of the test sample to be fired, up to twenty (20) cartridges. When
the test consists of more than twenty (20), but not more than forty (40) cartridges, then twenty
(20) standard reference cartridges shall be fired, when the test consists of more than forty (40)
cartridges shall be fired, when the one (1) standard (reference) cartridge shall be fired for every
two (2) test cartridges.
30.2 After the required number of standards (reference cartridges has been fired, the actual
average chamber-pressure of the standard (reference) cartridges shall be compare with the
assessed value. If the assessed value is higher than thee actual average chamber-pressure of the
standard (reference) cartridges, the difference is a plus correction and shall be added to the
average chamber-pressure of the test cartridges. If the assessed value is lower than the average
chamber-pressure of the standard (reference) cartridges, the difference is a minus correction and
shall be subtracted from the average chamber-pressure of the test cartridges. If the assessed
value and the actual chamber-pressure of the standard (reference) cartridges are identical, then no
correction is applied.
30.3 The pressure-barrel assembly will be acceptable provided the results obtained with the
standard (reference) cartridges are within ± 3500 PSI of the assessed value.
30.4 It is suggested that control charts be maintained for record purposes, of the results from
each barrel in which standard (reference) cartridges are fired. Every correction obtained shall be
compared with the previous ones to determine whether the test conditions remain stable to a
certain degree.
30
For Parts Inquires submit RFQ to Parts Hangar, Inc.
© Copyright 2015 Integrated Publishing, Inc.
A Service Disabled Veteran Owned Small Business