This is the link provided from paypal........www4.law.cornell.edu/uscode/html/uscode18/usc_sec_18_00000921----000-.html
Disturbing part
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(C) any muzzle loading rifle, muzzle loading shotgun, or muzzle loading pistol, which is designed to use black powder, or a black powder substitute, and which cannot use fixed ammunition. For purposes of this subparagraph, the term “antique firearm” shall not include any weapon which incorporates a firearm frame or receiver, any firearm which is converted into a muzzle loading weapon, or any muzzle loading weapon which can be readily converted to fire fixed ammunition by replacing the barrel, bolt, breechblock, or any combination thereof.
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What about the cap & ball revolvers that have the cylinders you can change out to shoot .45 Colt? (I realize it is a "firearm" if the cylinder is installed, but this sounds like it is a firearm even if it isn't)
Shit!
Can someone show me the federal law where it calls these "non-firearms"?

(16) The term “antique firearm” means— (A) any firearm (including any firearm with a matchlock, flintlock, percussion cap, or similar type of ignition system) manufactured in or before 1898; or (B) any replica of any firearm described in subparagraph (A) if such replica— (i) is not designed or redesigned for using rimfire or conventional centerfire fixed ammunition, or

Wouldn't this cover those pistols? How close of a copy are they?

I was going to sell one and I was going to use PayPal, as I thought this was clearly a "non firearm" (that's what it says in every catalog), I had my mom looking over my shoulder and she was freaking out and telling me that she was shure that this is a firearm.

Now that I think about it............A Ruger isn't really a copy, I guess if one person made a conversion it would make it a firearm?