I was just over at my local gun store
(Bill's Gun Range, Robbinsdale,MN) and
a friend of mine thats works there show me
something that I thought was'nt legal,
he just got in a complete lower reciever
of a AR15 from Rock River for a customer
that odered it, and the person that ordered
it is not an LEO, and the order went in to
Rock River as a normal order, the lower had
a M16 hammer, yes I know what a M16 and a AR15
hammer looks like, I thought by the ATF that
if you have any parts from a M16 in your AR15,
they say your in violation of the law,
class 3NFA thing, Am I missing something here ?
or can I have a M16 hammer or even a M16 bolt
or not ?

you cannot have any (read: not one) M16 fire control part in a semi auto AR15.  perhaps the hammer you saw was part of a 2 stage trigger.

That's not true.  Its [b]best[/b] not to have 1 M16 part - but the law indicates that your asemlage of parts had better not be able to fire full-auto.

This has been covered ad-nauseum in the
Legal section (by lawyers versed in the law).

I agree with Forest, My friend and I both have
Preban Colts. Mine has all ar15 parts and he has m16 parts (no auto sear),says the parts are heaver and work better. I just got a new .22 convertion kit and we went to try it out at the local rifle range. I shot almost 150 rds and then he wanted to try it in his rifle. So he installed it and pulled the trigger and empited a 30 rd clip. He had the selector on auto and the gun went auto. Now he does not have the sear in his gun, but has all the other parts. Needless to say he will put his ar15 parts back in ASAP. Anyone seen this b4?
Only one other shooter at range that day (Vet.)
His only remark was "Hot damn"

i saw this happen once. back in the 80's when most were built with m16 parts. if a m16 saftey/selector is flipped to auto the rifle will slam fire when the bolt closes a very dangerous condition!!the rifle will fire even if the bolt is not fully closed causing a major case blow out  one should never place a rifle to full without the auto-sear in place

I suppose it is possible one snuck in but I would be suprised since RRA does not deal in NFA items or parts why would they have M16 parts lying around?

Are you sure you didn't see one of the "new" style hammers that all the manufacturers are going to? They're no longer putting the notch in the front, because they're no longer cutting the bolt carriers under the firing pin.  Colt startes it awhile back, and all the others are following, as far as I can tell.

Just got a DPMS lower a few weeks ago, with the same thing. Front of the hammer looks like M16, but it does not have the lug on the rear, that catches the auto sear.

A worthy changeover, in my opinion.  That firing pin catcher was never part of the federal regs in the first place, and eliminating it gives you a bolt/carrier assy that's closer to the weight Gene Stoner designed the rifle to have; which gives you more reliable function