Hi Wayne, my understanding is that commercial ammo companies load the older shells to a minimum pressure, unless specified. The 32-20 or the 32 WCF was originally a rifle cartridge that was also later used in handguns. I use cowboy loads in old "timey" cowboy guns. If I was concerned about the 32-20 I would use "Black Hills" Cowboy loads. I have shot those in the above revolver w/o signs of pressure. I also reload so that is a different option. I can only say I never had a problem, regards, Mike