Depends on markings on upper.
Yes
a gunsmith needs to check both the ammo and rifle.
Have it checked over by a good gunsmith before you attmept this.
5.56 and 223 cal. are the same cartridge...........
yes, but don't shoot the P ammo too often
45 ACP
.45 Long Colt.
Colt made a single action army revolver that used 32.23 ammo & I believe Winchester, Colt lightning, Savage & Remington made 32.20 rifles,if that answers your question
yes. the 5.56 is the 223 caliber ammo.
DON'T DO THIS UNLESS THE MAKER SAYS IT IS SAFE TO DO SO!!!!!!!!!!!!!!!!
No. You will have to have a Model 1895
AR15, M16, M4, Ruger Mini 14