I was reading through the active threads and came across one where someone said that they got into trouble for having a SBR with a M16 trigger group and M16 carrier.  I can see the trouble with having an unregistered SBR( I assume that it was unregistered since he got into trouble).  I can see having a M16 trigger group would get you into trouble because that would make it an automatic weapon (at least as far as I can tell putting the M16 trigger parts into an AR15 would make it an automatic weapon.  What I am confused about is the M16 Bolt carrier and bolt.

I've read on some other threads that the M16 bolt carrier and bolt were better than the AR15   bolt carrier and bolt.  That changing them would be mean stronger parts that would last longer.  If that was the case then I was going to get one.  

Now I'm confused.  Does putting a M16 Bolt and Carrier into an AR make it into an illegal firearm?  If so why?  I mean without the trigger group the rifle is still going to be semi auto.

Thanks

That thread was complete BS, and was just a troll trying to get a reaction. You're good to go w/ an M16 BC in your AR.

Yeah, disregard the post in question.  A FA bolt carrier does not change the weapon's classification.  

You have to do some machining to the upper to make the rifle full auto just parts will not do it, I am not sure but I do not think a M16 selector and disconector will even work in an AR. That is where the machining comes in to make room for them.
I busted a guy on a warrant while the arrest was going on we found in plain view a bunch of AR parts and M16 parts he was building full auto M16's out of AR uppers and lowers.
Short story is ATF didn't do any thing with him as none of the FA rifles were assembled. just having the parts is not illegal, of course him having the lowers( and being an excon) was enough to pull his parole, and send him back to the joint anyway, and the warrant was only for some unpaid tickets,  talk about having a bad day!'Gee I sort of miss them old days when I was a working cop.

I think it makes very little difference to run a regular M-16 carrier, But it can't hurt. It adds a tiny bit of weight, so it reduces recoil a tiny bit. Every little bit helps according to what I've heard. I read somewhere that M-16 carriers are held to tighter tolerances than AR-15 carriers, smells like bullshit to me.

And while the bolt carriers may differ, there is no difference between bolts for M16's and AR-15's.

Quoted: Short story is ATF didn't do any thing with him as none of the FA rifles were assembled. just having the parts is not illegal, ....

I don't know why the ATF declined to prosecute in this case, but "just having the parts" can definitely get you into big trouble (M16 bolt carrier does not count). They call it "constructive intent" (i.e., why would you have the FA parts if you didn't intend to construct the weapon?).

This is the first time I have ever heard of the ATF not jumping on an opportunity to screw someone in any way possible.

Selective enforcement?

Having the parts, is the same as assembled. The M-16 carrier has some desirable features. You can get all the good and none of bad by using a STAG carrier.

Batf choice of who to screw is baffling! Since they are now part of the Dept of Revenue money is probably there goal.

Quoted: Batf choice of who to screw is baffling! Since they are now part of the Dept of Revenue money is probably there goal.

If you mean the Treasury Dept, they always were. BATF is a tax collection organization. When it prosecutes a violator, it's essentially because the culprit didn't have permission and pay his tax on the illegal firearm, alcoholic beverage, or tobacco product.

If BATF didn't prosecute on contructive intent, it was probably because the dude was going to the slam anyway on parole violation, and they can always come back within the statute of limitations, and prosecute on the federal charges, if they don't think he served enough state time on his revocation.

Quoted: Quoted: Batf choice of who to screw is baffling! Since they are now part of the Dept of Revenue money is probably there goal. If you mean the Treasury Dept, they always were. BATF is a tax collection organization. When it prosecutes a violator, it's essentially because the culprit didn't have permission and pay his tax on the illegal firearm, alcoholic beverage, or tobacco product. If BATF didn't prosecute on contructive intent, it was probably because the dude was going to the slam anyway on parole violation, and they can always come back within the statute of limitations, and prosecute on the federal charges, if they don't think he served enough state time on his revocation.

You a correct in that they allways WERE part of the Treasury Dept. HJowever, the ATF now falls under jurisdiction of the Justice Dept., which it now baffles me how they can enforce Tax Code..

The same way that Customs (ICE) does. You enforce the laws as Congress tells you to enforce. The only tax that ATF still gathers is on NFA transfers. All other taxed are collected by ATTTB (Alcohol and Tobacco Tax and Trade Bureau) that remained in Treasury.