… we may as well share with you the overhaul manual on the M1/2/3 carbines. You know, these things:
This edition of FM 9-1276 was published in 1947 and it contains a lot of useful information, including the overhaul flow chart we’ve already shown you, and the very interesting inspection and rebuilt-weapon serviceability standards.
Most gun-culture types have a certain fetish for MilSpec and seem to think that military specs are always higher that civilians’ standards. Well, it depends on the civilian! But the military has looser requirements than you might think, and one characteristic of these requirements is that a weapon in the hands of troops is not required to meet standards of a weapon freshly rehabbed, or one being mothballed (figuratively) for that matter. For example, when the M16A1 was standard issue, one could be turned in for higher-echelon maintenance if the barrel was shot out. How shot out? The depot didn’t want to see it if it could still achieve seven (!) minutes of angle. Needless to say, crappy-shooting M16A1s were pure hell for a unit armorer to get rid of.
There are a few examples of this very, very low bar attending to the M1 (and M2 and M3) carbines. One of the most interesting is the high tolerance for pitting in the inspection standards. A barrel was only unfit if the pits were wider than a land or a groove, or longer than 3/8″. Pitting across most of a groove? Well, that was OK, then. Just so long as it’s not all the way across.
Anyway, here goes: