RE: .54 vs .58 roundball barrel
 

The few civil war replicas rifle I had a chance to shoot, (and one original Springfield for 1800's) had a strange sighting system as it was explained to me. The men were told to aim for the belt buckle of the enemy troops and the gun was setup to shoot very high. The belt buckle sight would normally put them in the chest area as it was explained to me by some reenactors. And when the troops were long distance, then all they had to do was aim for the head and the bullet drop would then again, place the Minnie in the chest area.

Most of the guns to my understanding were set to shoot 60-70 grains of powder for their best accuracy. This was done for a couple reasons.. that much powder they found was plenty of powder, gave all the power they needed, saved on powder volumes used in battle, and produced the least fowling. When in the battle field, fowling could be the difference between life and death. They needed a slip fit projectile that did not fowl the barrel out. The Minnie ball solved that problem real well. Also with the extreme weight of the projectile, any thing in the body was an almost sure guarantee that the solider struck was out of the battle and with the medical facilities they had was probably out of the war.

Enfields, Springfields, Zouave, Sharps, Whiteworth, Gibbs, and some of the older rifles muskets and muskets were deadly in the right hands as the overall numbers of dead and wounded for major battles was a sad testament to.

I personally have always been interested in the .69 caliber rifled musket. I believe they were the 1842 model. They were originally a smoothbore but some of the muskets were rifled with a very slow twist that allowed them to throw that .69 caliber (12 gauge) ball down range with some excellent accuracy. Getting hit with anything from that would not have been a good experience. I think that would be a fun rifle to shoot.