Senate bill S.1878, which failed in 1994, attempted to require a 0 federal "arsenal license" and allow federal home inspections of private collections of 20 guns, or one carton (standard retail package) of reloading primers. It would also ban small handguns, magazines holding over 6 rounds, "non-sporting" amunition, and require a state license to buy a handgun, ammo, or parts.

LAWFUL FIREARMS OWNERS BEWARE!
Many people say "It will never happen", but it happened in the UK, Canada, and Australia, and it is already happening in parts of the U.S.A. (New York, California, Washington D.C., etc.)

Be sure to read the comments, you will find more information about federal firearms license