Bob the round was not replace the pistol. It was to give the soldier something a bit more reach than their side arm.
Taurus makes a DA revolver in .30 Carbine. Ruger makes a single action Black Hawk in it. The Black Hawk is real hoot to see it fire. Huge muzzle blast, with a long bright flame. Big boom, a lot of flash, and minimum recoil.
No matter how many times you do it and nothing happens it only takes something going wrong one time to kill you.