Technical data

TM 9-1005-319-23&P 0029
0029-6
GENERAL INSPECTION CRITERIA - Continued
Table 1. 5.56mm Rifle M16A2/M16A3/M16A4, M4/M4A1 Carbine - Continued.
Item Standard
Front sight and gas tube ........ Inspect gas tube for proper alignment with carrier key. Gas tube must not
bind when mating with the key.
Evidence of gas leaks around the front sight connection of the gas tube shall
be cause for rejection until rifle has been function fired to determine if the
loss of gas is sufficient to cause malfunction. If malfunctions occur during
function firing, repairs are necessary.
Inspect front sight for damage.
Bolt carrier group.................... Inspect bolt for elongated or oversized firing pin hole using plain cylinder
gage 12620101.
Firing pin holes which permit the plain cylinder plug gage to fully penetrate
at any position on the circumference will be rejected.
Bolt face with a cluster of pits which are touching or tightly grouped, covering
an area measuring approximately 1/8 in. (0.31 cm) across will be rejected.
Bolts which contain pits extending into the firing pin hole will not be rejected
unless firing pin hole gaging check determines rejection.
Bolts which contain individual pits or scattered pits will not be cause for
rejection.
Only phosphated bolt carriers are acceptable. Both phosphated and chrome
plated bolts are acceptable for Air Force use; only phosphated bolts are
acceptable for Army use.
NOTE
(Air Force Only)
Use of non-serrated bolt carriers is acceptable for all mission requirements. Use of
chrome plated bolts and/or bolt carriers are acceptable for all mission requirements.
Use of any style extractor spring is acceptable for all mission requirements, replace
extractor spring only when they no longer enable extraction of cartridges.