I have a copy of the M16A1 Spec but it doesn't cover what I think you are asking for. To obtain what you are asking for you need the TDP (Tech Data Pack) which consists of the production drawings for each individual part. The TDP at one time was restricted for gov't use only. When the first ARs hit the street their dimension was derived from reverse engineering. You could write Rock Island Arsenal and ask if you could buy the TDP. It might be for sale now that the A1 is all but out of the system and replaced by A2.
Spare parts are purchased independently and first article is presented for acceptance to Rock Island Arsenal and they are submitted to the gage series. If they fail initial gaging the entire lot is rejected. The vendor is allowed to sell the parts to recoup production costs. A friend was the PCO (Procurment Contract Officer) for M16 parts and he estimates that 95% of the parts floating around for sale won't meet the drawings.
The spec for procurement lists things like cyclic rates (new) Dispersion acceptance (4.5" or less at 100 yards) (rejection 7.2" Max dispersion at 100 yards) and be within a specified rectangle that was about 12X18 inches with rear sight in middle of travel and the skirt of the front sight even with the lowest level of the U formed by the front sight. Round life was 6000 rounds.
Now the rest of the story. If a rifle doesn't print in the larger outer boundary the gunner removes the rifle from the hard mount and the front of the in a 3 pin fixture and they bend the barrel to make it hit within the boundary.
There is a saying the the Army Small Cal Lab--"If it won't shoot straight bend it, if it won't shoot bent straighten it." I have seen weapons that shoot dead on the money at 100 yards that are bent left, right, up and down.