ligonierbill
New member
Just to put a few facts out there. I don't shoot .327 mag, but I do shoot all the other 32's. The base diameters of 32 ACP and 32 S&W Long are identical - 0.337 in. The auto tapers a bit to 0.3365 at the neck, while the S&W is straight walled. Both shoot 0.311 to 0.312 bullets. Spec pressures are a little different (these are CIP): 32 S&W Long 1,000 bar (14,504 psi) vs. 32 ACP 1,600 bar (23,206 psi).
If you are shooting the auto rounds out of a revolver designed for 32 H&R (CIP 1,620 bar), you're fine with regard to pressure. If you are shooting it in one designed specifically for S&W Long, like the Colt Police Positive or the S&W Regulation Police, 32 ACP is way over pressure.
If you are shooting the auto rounds out of a revolver designed for 32 H&R (CIP 1,620 bar), you're fine with regard to pressure. If you are shooting it in one designed specifically for S&W Long, like the Colt Police Positive or the S&W Regulation Police, 32 ACP is way over pressure.