I was concerned about differing specs between the manufacturers, which was why I started measuring stuff in the first place, but the while the chambers of the cylinder would appear compatible with the bore diameter, the GROOVE diameter is what's puzzling. The exterior of the barrel is marked with the typical ".44 CAL", but this thing has a groove diameter closer to what one would expect on a modern .45 rifle. Without slugging again starting with a fatter chunk of lead, my impression is that if one were to use this barrel for modern cartridge practices, you might be wanting .458-.459" rifle bullets. Seemingly inappropriate for anything you'd call a .44.
From what I can piece together on lube, the cylinder face oversmear thing is a modern range practice. You aren't going to ride around on a horse or dive for cover on a battlefield in July with blobs of grease melting out of every chamber or attracting sand.
Underwads? Maybe, but lubed with what? The whole ammo stack gets compressed on loading, and lube squeeze and powder contamination would be my next concern. Fine if you're immediately shooting it out, but after marching 8-10 hours?
I've seen period Colts displayed in cases with accessories - often including a dual bullet mold casting one round ball and one conical. The conicals tend to have grooves - presumably filled by hand with the goo of choice prior to loading? Pre-fabbed flash paper cartridges were certainly a thing, but probably not assembled by a busy lieutenant with troops to supervise. And if that's your primary method of propulsion, then why all the flasks?
Of course we know that use of some form of bullet lube has its advantages, but I'm looking at battlefield practicalities of the 1860's. If there's a period method for lube with a round ball, I'm open to it.
I fired about 6-7 cylinders worth yesterday of unlubed balls. Difficulty of loading did not increase throughout the session. Barrel fouling appeared to be carbon only (no leading), and fairly easily removed with a post-session hose-down of moose milk and application of a nylon brush. Primary operational difficulty (when it wasn't fired cap jams) was rough cylinder rotation apparently caused by crud building up on the rear of the cylinder. Removing the cylinder and rubbing front and rear faces against the carpeted top of the range bench restored function well enough to continue. Since the cylinder spins fine when everything is clean, I'm left wondering if I took enough material off the ratchet surface when fitting it. As best I can tell, there is no provision for endshake on these things, so I'm hesitant to polish off any more without some tolerance guide I could check with a feeler gauge. Anybody got an Italian armorer's manual?