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...........
45 ACP
yes, but don't shoot the P ammo too often
.45 Long Colt.
yes. the 5.56 is the 223 caliber ammo.
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
No. You will have to have a Model 1895
DON'T DO THIS UNLESS THE MAKER SAYS IT IS SAFE TO DO SO!!!!!!!!!!!!!!!!
AR15, M16, M4, Ruger Mini 14