[ccmay]

That device (the AR-15 drop-in auto sear, or DIAS) is strictly controlled. Any of them made between 1981 and 1986 are considered to be machine guns and must be serial numbered and licensed just like a real NFA machine gun. None can be made legally, except for law enforcement use, since May 1986.

There were some in circulation before the BATF and Congress tightened things up in 1981, and these were grandfathered in, so it is possible to buy an unregistered drop in auto sear. However, the legal unregistered ones are 1) expensive, 2) illegal to own if you also possess an AR-15 rifle or even certain combinations of AR-15 and M-16 parts, and 3) don't fit in most newer AR-15 guns anyway, as Colt modified them to prevent using the DIAS device back in the 80's.

-ccm

[Dead Corpse]

The DIAS also requires ALL of the other M-16 fire control parts for it to work. You can't just drop it into an AR-15, with semi-auto fire control, and expect to rock-n-roll.

A lightning link might do the trick. I've heard of them, but never seen one. Again, the link itself would be considered a "machine gun" and require all the Class III Bravo Sierra that goes along with it. So much for an "inalienable Right".

The registered shoe-string "machine gun" for an M-1 is still the most ridiculous abuse of the Class III registry I have ever heard of.