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.
Quick disclaimer load the rifle according to manufacturer load data. what is safe in my rifle may not be safe for yours. There that part is done. That depends on what the stag horn mag rifle likes. The rifle can safely handle 150 grains of powder. black powder is measured by volume not weight. I have a staghorn mag. in 50 cal and it likes 100 grains of pyrodex pellets. I have shot 150 grains of both loose pyrodex and pellets but with no great accuracy. All because the rifle can handle 150 grains of powder doesn't mean it will shoot your bullet accurately. My rifle likes the 100 grains and I get decent groups. There are other factors as well bare in mind different bullets and will shoot differently too.
You can do this by miking the bore of the rifle,if you do not feel comfortable doing this you may have a qualified gunsmith do this for you.Most 25 cal bores are .257 diameter,the 32 cal bore may be .321 or smaller depending on what caliber it is chambered for.
No. Absolutely not. A felon may not purchase, possess, or have access to firearms. Period.
Jack First or GunPartsCorp may have one.
Unless there are markings on the rifle, these may be difficult/ impossible to verify. Some low cost rifles were imitators of name brands, and may be similar in appearance.
Depends on the .30 cal. For 30-06 ammo, the retail sales price may vary from about .30 to .50 (in US dollars) per cartridge.
This rifle was manufactured by Mossberg. It is the same rifle as the Mossberg model 50. Although there may be a slight difference in the sights available on the two models, mechanically they are the same gun.
I just purchased one for 100.00 though I think it may be worth more.
Start at Numrich gun parts corp.they may be found on the web.
Your rifle was made for Sears by Marlin- it is their model 81- a popular rifle. Parts may be available on their website from gunpartscorp, or any good gunsmith.
New York State does not have a caliber requirement for deer, except to say that rimfire rounds may not be used. A semi auto rifle used for deer hunting may not hold more than six rounds.
Sadly, not much. About 75-125 dollars. I have one myself. However, it may be true that the value will be rising within the fututre and that the rifle is getting rarer each year