FI Model D 380 jams

Question
Bought gun used, $200, Gun looks good, breaks down all pieces look good. gun looks like colt pony but jams. first after 1st round shot, then after polishing on barrel i can shot 2 and sometimes 3 rounds before jamming. (shell case ejects and bullet hangs in ramp)

Answer
I'm afraid you've learned by hard experience an unyielding  principle of economics - you get what you pay for. When someone pays $500 for a gun, what he's paying for is not just the metal & heat treating, not just the execution of the machining, but the engineering behind it to insure that it will work every time.