While not an issued weapon, many soldiers carried their own 357 Mags during the Vietnam War. One Platoon Sergeant (SFC, E-7 USA) carried a Smith & Wesson® Mdl 27 in a shoulder holster. Anyone he shot didn't get back up; no second shots required! All our Chopper Jockeys were issued S&W 4" Skinny Barrel Mdl 10's (38 Special). As late as 1984, Army helicopter pilots still carried Mdl 10's. (The 130gr FMJ load was pretty anemic IMHO.)
Only two defining forces have ever died for you:
1. Jesus Christ.
2. The American Soldier, Sailor, Airman, & Marine.
One died for your soul, the other for your freedom.