Proofhouse.com has Winchester sn data that will get you in the ball park.
what you have is a converted civil war 58 cal. musket. After the civil war those muskets were converted to 50/70 cal (trapdoor) center fire rifles. Later the 45/70 (trapdoor) came into being. Value depends on overall condition of the rifle................
Depends on which .50 cal, and which cartidge. If you mean a Barrett Model 82A1 sniper rifle, in .50 BMG, standard ball ammo is ABOUT 2800 fps.
no the rifle is 85 cal and is second lowest to the pistols
marlin 35 cal. lever action. rifle/ Marlin makes the rifle ,but not the ammo for it.
Yes, but the patch would need to be thin, normally you would fire a .490 ball and a .15 patch, so a .10 patch in this case would be a good place to start.
a 30-cal rifle or sniper rifle. closer to 30-cal
Contact the maker of your rifle for their instructions. It will depend on bullet weight. Assuming you mean a .50 cal MUZZLELOADER- and not a .50 Barrett- between 75 and 90 grains of ffG black powder is an average load for a patched ball.
No
When you say Air Rifle you are referring to a pellet rifle not a firearm. At present there are no 300 Cal air rifle being made.
The rifle is marked .45 but they messured this from land to land inside the barrel not groove to goove. a .433 with a .18 patch seems to be the common load. 45 is just to tight for the rifle
If it's a 1863 model then it would be a cap and ball model, not cartridge, and it would be about a 31 or 36 caliber. However, if the piece was converted to cartridge then it COULD be a 32 cal. cartridge.