"...what bullet would you suggest..." What bullet/ammo did you use out of the M1? Milsurp ball? Ever sight in? There's no need for a 'back up' pistol of any kind when you have a rifle. Leave the .45 at home. You had a rifle that you should have been ready to shoot. By your own admission, you don't have the skills required to be using any handgun in the first place.
"...Anyone who thinks..." If you have the skill to shoot it and if 230 gr Black Hills HP is used. Doesn't have to be +p. The OP clearly didn't have either the skill or the right ammo. Mind you, I suspect we're dealing with a troll.
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