I've owned two, 1851 Navy (med frame, 6 shot) and a 1862 Pocket Police (small frame, 5 shot, think of a Smith J frame with long barrel) both in .36 cal (.375 round ball or conical bullet). 3 main calibers, .31, .36 and .44. Small concealable guns such as the Colt 1849, bemonmoths such as the Walkers and Dragoons, to the belt guns (med frame) of the 1851 Navy and 1860 Army. If you want to shoot allot get a steel frame over brass. There were also DA besides SA guns. They look at the LeMat for a 9 shot .44 with a 20 gauge barrel in the center.
I cast my own round .375 balls for my guns. Picked up the Navy in a trade back in 91' and then drove down to Dixie Gun Works in TN (at Ft Campbell Ky at time) and got the Pocket Police. Colts black powder guns didn't have a top strap where Remington started with one with the 1858 Army. Smith and Wesson held the patent on bored thru cylinders till their patent expired in 1872 and then Colt took the grip frame of the 51' Navy, added a top strap on top of their 1872 centerfire gun to come up with the 1873 Peacemaker.
Suggest you handle a few to get a feel for the balance. Notice the frame as some are boxy and others more streamlined. Rammers became more effective as time went along too. Compare a 51' Navy to a 60' Army.
CD