This heavy 45 Auto Rim standard pressure loads utilize high quality Starline brass with flash-suppressed powder to shoot in the dark without blinding yourself. It is the ballistic equivalent of +P 45 ACP loads, yet they operate at standard 45 ACP pressures. They loads are safe to use in any 45 ACP revolver that is in normal operating condition, including any model 1917 Colt or S&W revolver.