All World War II .30-cal. M1 Carbine ammunition was manufactured with non-corrosive primers. If the barrels were not routinely cleaned, there were no corrosive primer salts to ruin the bores.

Redesigned barrels and sights had increased its accuracy and ruggedness. Still a tough rifle to produce, the Garand was coming out of the Army’s Springfield Arsenal at a 560-per-day clip.