Gunsmith advice: Shooting a .45 Super in a .45 ACP +P …
Mainly Arizona. Hi gentlemen, The 45 Super, developed in 1988 by Dean Grennell, another well known gun writer, is dimentionally identical to both the 45ACP (21K PSI) and the 45ACP +P (23K PSI), but it was created with a stronger case that can handle the higher pressures of about 28K to 39K PSI: See Wiki Link on .45 Super.