I bought a Colt revolver that is labeled "Commando" on the barrel this week. It has grayish/black parkerizing (about 90%), reddish plastic grips, and no military markings.Serial number is 43404. There is the letter "I" on the butt of the grip frame. I know it is a wartime government purchased handgun. What is the meaning of the "I" ? It was priced at $185 OTD at a pawn shop so I had to have it since it was tight and in very good condition. I think I'll remove the plastic grips for safe keeping and use this one as a shooter. Would the FBI load of a 158 gr. +Plead HP be a good load for general use?