I would like to know if I could use an M16 bolt in my AR15 project gun?

Would I be breaking the law (assuming it would function properly) if the M16 bolt was installed - but no other M16 parts?

Thanks for your help.

yes it will work and yes it is illegal. it dosent matter if you have one or all parts to make it an auto.

Thanks Stinger. You have saved me from potential trouble. I am glad I asked!

This topic has been hashed around before. I'd give the link but its no longer listed in the Legal section topic list.

To save time and avoid another drawn out discussion, I'll cite the NFA definition of a machine gun.

[url=http://www4.law.cornell.edu/uscode/26/5845.html]26 USC 5845[/url]


Only one M-16 part*, in this case you mean the bolt carrier for the bolts are identical, will not suffice to make your AR shoot automatically as a machine gun. Therefore, it may not be wise to stockpile M-16 parts in that you may accumulate enough to be "in the possession" of enough of them to make an "automatic" machine gun, it is not illegal to use an unmodified M-16 bolt carrier in a non-NFA rifle.
Its even been stated that Colt sold civilian 9mm carbines with M-16 bolt carriers.

(* Auto Sears are a different issue, see the "any part designed and intended solely and exclusively" language.)

Cheers, Otto

I found the link I was refering to above, but upon rereading it, I don't want to send you into such a mess. My answer above should suffice.
And according to the thread they were Colt Green label 9mm's.


If someone insists, [url=http://www.ar15.com/forums/topic.html?b=1&f=6&t=147440] M16 bolt in AR15?  [/url], but it gets ugly.

Also, here is the ATF weighing in on the subject. The third paragraph of the [url=http://www-2.cs.cmu.edu/afs/cs/user/wbardwel/public/nfalist/atf_letter52.txt]March 1999 letter [/url] states the same thing I did above.

Cheers, Otto

I have M16 bolt carriers in all my ARs, because I'm convinced the added weight, compared to the usual cutaway all over the place AR carriers are too light weight, and contribute to wearout and malfunctions.  That being said, I've always cut back the shoulder that trips the auto sear back about 3/8 inch, just to be on the safe side legally.  Only takes a few minutes w/a small grinding wheel in an electric drill[:D]

I think you will find that the carrier is the illegal part, not the bolt.

Actually, there is no official ruling or formal ban on the use of M16 parts in an AR-15.  ATF "advises" against it, because they claim they can easily make your AR-15 fire automatically if you have an M16 hammer and bolt carrier installed.

However, unless you have a complete set of parts to turn your AR-15 into an M16 (including the auto sear and pin), or [b]the rifle fires more than one shot per pull of the trigger with the M16 parts installed[/b] you have not broken any law.

Wow...this is a double edged sword. I see both sides of the arguement, and both seem to be valid...depending in what mood I am in. I think I need some Advil.

Change that...Whiskey and Coke. [B)]

Circuits:
What I think the ATF does in the case you mention about an M-16 bolt carrier and hammer is that they intentionally make the weapon malfunction by using soft pistol primers and remove the disconnector, therefore allowing the hammer to follow the carrier and maybe fire the next round. So if they can make your rifle malfunction, it is an unregistered machine gun.  I've seem more reliable slam fires with improperly seated primers than this.

I agree with your no official ruling statement and I wish I could find a better reporting of the case, United States v. Corcoran, where Judge Donald E. Zeigler said, in explaining why he was dismissing 6 counts of possessing or transferring unregistered machine guns:
         [i]"The AR-15's in this case were transferred by defendant without automatic sears.  The essence of due process of law requires that the government make clear that conduct which constitutes a crime.  Here, the ATF ruled on November 1, 1981, that an AR-15 with M-16 internal components already installed, will convert to a machine gun with the single addition of an automatic sear.  It is inescapable that without the automatic
sear, the AR15 with M-16 components parts is not a machine gun and need not be registered.  If it did constitute a machine gun, because it may fire more than one round with a single function of the trigger, the agency was required to make that clear in the Federal Firearms Regulations, especially in light of ATF Ruling 81-4 effective November 1, 1981.

         "In short, once Ruling 81-4 was made and published, the agency was required to supplement that ruling to make clear that conduct which was once legal, or at least arguably legal, was now prohibited.

         "In addition, the arguments that the agency did change its policy, in letters to interested citizens after November 1, 1981, is without merit.  The change must be published in the same manner that the original ruling was published; otherwise citizens who relied on Ruling 81-4 but did not inquire of the government could be prosecuted for a crime while other citizens could not.[/i]"
[b]United States v. Corcoran[/b], Criminal No. 88-11 (W.D. Pa. April 5, 1988), transcript, pages 39-40
(quoted from [url=http://www-2.cs.cmu.edu/afs/cs/user/wbardwel/public/nfalist/ar_15_auto_sear_faq.txt] NFA and other gun law related info and cases: Pre-81 AR-15 Drop-in Auto Sears[/url])

All I know is that this was a federal case in Pennsylvania in 1988, so this was prior to a few amendments to the NFA and I don't know if it is still or ever was controling law.

Cheers, Otto

Double Whiskey and Coke.

It is legal, and yes, I have one, because it was on the upper the US Marshal sold me.

[beathorse][>:/]

The law seems to be that it's ok as long as it doesn't go auto. I do seem to remember a letter ruling from ATF that was posted on one of these threads that said that M16 parts were ok as long as they were modified to ar15 specs. This is just my recollection; I can't find it anywhere.

Best advice seems to be just to avoid it if at all possible.