Sure enough, the only way to determine the precise caliber of a rifle is to have a gunsmith check it (or do this yourself)... nevertheless- I have a .58 cal "Richmond" Rifle (reproduction). Lyman's ".58 cal mold, 510 Gr. (Item #2651213)" produces a tight fitting Minie Ball that is frighteningly accurate. Today I purchased a very sweet 1861 Tower Artillery Carbine (complete with nipple cap on a chain), an original- not a repro. I am surprised to find my Lyman .58 Minie Ball (noted above) fits considerably more loosely in the muzzle. I always thought Enfields and Tower Rifles were really .577- so rather than my ball being too tight as I had expected, it appears too loose. What mold is best for ".58 cal 1861 Tower Artillery Carbine"?