FRANKFORD ARSENAL PHILADELPHIA PA AMMUNITION DEVELOPMENT AND ENGINEERING LABS
This report is concerned with a limited investigation of the 5.56mm cartridge, lot LC-12387, fired from M16A1 rifles using the standard flash suppressor, FSN-1005-933-8089. Two 5000-round confirmatory tests were fired in M16A1 rifles at Frankford Arsenal using ammunition lot LC-12387. These tests have indicated the adequacy of this ammunition when fired in standard rifles with standard flash suppressors. There was no significant accumulation of cartridge residue in the bolt-carrier group of either of the test rifles. Residue accumulation in the gas tube appeared normal as indicated by air flow readings and weight measurements. Review of test data contained in U.S. Army Human Engineering Laboratories USAHEL Letter Report No. 88 has indicated that the use of noise suppressing muzzle attachments can seriously affect gas tube life in the M16A1 rifles.