I will try to help with your question. Using U.S. TM 9-1904 Ammunition Inspection Guide dated 2 March 1944 page 335 there is a brief discussion in the differences of projectiles due to gun construction. It is confusing, as it appears that the guy that wrote it might have mixed the gun specifications back and forth. The manual states as follows:
"Differences in weapons also require variations in projectiles. For example, since the M4 (Aircraft) Gun is lighter than the M1A2 (Antiaircraft) Gun, the projectile of SHOT, AP, M80 is the same as the projectile SHOT, AP, M74, only shorter and lighter in weight. Another instance is in the case of SHOT, A.P.C. (Armor-piercing-capped), M59, which is similar to SHOT, A.P.C. M51, except that the chambering mechanism of the M1A2 Gun requires that the windshield of the M51, for the M3, M3A1, M5, and M6 Guns, be omitted in the projectile for the antiaircraft gun."
I will see if I can find anything else in other manuals.