This is a worldwide community to answer questions. You will have to define the meaning of "Mn". Is that supposed to mean something or was that a typo?
You need to find a lawyer who is familiar with firearms law to get a correct answer.
"A rifle kicks." first law second law third law
You will need to contact the local law enforcement for current an correct inforamtion
You need to talk to the lead law enforcement agency or a lawyer familiar with the laws of wherever riverside is.
Physically, it could be done. Highly doubtful it would be worth it to do that, rather than to buy an existing air rifle. Legally, a new receiver would have to be used - BATFE law dictates "once a machine gun, always a machine gun".
No. In all United States, pointing a fire-arm at someone in a non-self defense situation unless you are a law enforcement officer is strictly illegal.
Under FEDERAL law, yes- but check your state laws. A muzzleloading rifle that uses flint or percussion caps is not a firearm under Federal law, it is an antique- no matter when made. This does NOT apply to #209 primed rifles.
No. As a matter of fact, if you were convicted of a felony, it is against the law for you to ever possess a rifle.
Any purchase from a firearms dealer is regulated by Federal law. That law requires that the buyer of a rifle/shotgun be at least 18, handguns 21.
Federal law.
It has to be unloaded.
It could mean one of two things "FireArms Certificate" in Canada or United Kingdom "FireArms Certificate" in England. It's a Certificate from Law enforcement to own a high powered air rifle