M-16 bolt carrier in an AR-15

[kaferhaus]

It's NOT illegal. Those are ATF guidelines for company's manufacturing ARs. If you don't have enough parts to make the gun go bang more than once with one pull of the trigger, or in a condition that it can be readily adapted to do so, you are not in violation of the law.

Auto-sears are considered "machine guns" in and of themselves, so obviously that part would be a no-no.

If you possess an AR15 and the M16 fire control parts, you're breaking the law.

Many DCM shooters use the M16 carrier, including me. There's a simple reason for it. It is heavier.... it keeps the bolt locked for a tiny fraction of a second longer which reduces primer set-back and blown primers. It has nothng to do with making the gun full auto.... all the 16 carrier does in that capacity is trip the auto-sear.... which releases the disconnector....without the sear, 16 disconnector, 16 hammer, selector and trigger.... you're not gonna get more that one round off with one pull of the trgger.

The only 16 parts I own are carriers, Many many thousands of early ARs were manufactured with M16 bolt carriers.

 

[Zak Smith]

Oh wait, I think I have an M16 barrel and upper receiver around here somewhere. :banghead:

Get a grip.

We might as well pretend the AWB is still in effect 'cause the ATF might try to convict you for possessing your LEO mags or threading your barrel before it sunsetted.

-z

 

[socomcen]

I don't see the ATF going around ceasing the Colt SP1s and 9mms that were sold with full auto carriers, I would say thats because they're legal. :banghead:

But using one does put you that much closer to having a machinegun. Just make sure your rifle doesn't double and you're okay.

 

[Onmilo]

Come to Illinois and tell everybody how legal your M16 carriers are.
I love when people from states that allow civilian possession of class 3 weapons tell the rest of us how "Legal" machine gun parts are in a semi automatic firearm.
Count your blessings that you live where you live.

 

[Zak Smith]

I love when people from states that allow civilian possession of class 3 weapons tell the rest of us how "Legal" machine gun parts are in a semi automatic firearm.

Rhetorical question: Is an M16 barrel a machine gun part?

 

[ether]

I don't know if one MG part is illegal or not, but I was under the impression that any M16 part that is related to fire control cannot be used in an AR15. I think the ATF is only concerned with "M16" parts that are involved in fire control. The AR15 bolt carrier has nothing to do with fire control other than cocking the hammer, but the M16 bolt carrier does. In M16 full auto mode, the underside of the bolt carrier trips the sear as it goes into battery and releases the hammer for the next shot. I won't use M16 bolt carriers because it just seems to me there are legal reasons for manufacturers going out of their way to make a different bolt carrier specifically for the AR15.

 

[Zak Smith]

In M16 full auto mode, the underside of the bolt carrier trips the sear as it goes into battery and releases the hammer for the next shot.

It trips the M16 autosear which is not present in a semi lower assembled with AR15 parts.

 

[ether]

Exactly, it's just one of several required parts, which is why I don't know for sure if just one part is illegal, but then we get back to the question of why manufacturers feel compelled to make a different carrier for the AR15 when most people agree the heavier M16 carrier would be preferable.

 

[Jeff White]

ether,
The manufacturers feel compelled to make different carriers for the AR15 type rifles because the Feds make them. The BATF has to approve any design. The following is from Black Rifle II The M16 into the 21st Century by Christopher R Bartocci pp 233-235:

Colt's began the process of seeking approval to produce a semi-automatic only variation of their AR-15 rifle for commercial sale by submitting a prototype semi-automatic only version, serial no. GX4968 (Gun Experimental no. 4968) to the Treasury Department on October 23, 1963. A selective-fire rifle was also provided for comparison purposes.

Colt listed the following nine changes which they had made to the semi-auto version to prevent its re-conversion to full-automatic fire:
1. Removal of the automatic sear.
2. Elimination of the automatic sear hole in the lower receiver.
3. Elimination of the automatic sear well in the lower receiver.
4. Removal of the automatic sear hook on the hammer.
5. Removal of the automatic sear trip notch from the bottom rear portion of the bolt carrier.
6. Modification of the selector to eliminate the automatic setting.
7. Elimination of the "AUTO" position identification marking on the lower receiver.
8.Mechanical restriction of selector lever movement to two positions only: SAFE and FIRE.
9. Enlargement of the front pivot pin holes in both upper and lower receivers, and use of a larger-diameter front pivot pin.

On October 25, 1963 the Treasury Department advised Colt that in addition to these nine changes, they wanted the upper and lower receiver pin lugs relocated, in order to further prevent the interchangeability between semi-auto-only and selective-fire receivers. This was done by moving the enlarged pivot pin holes in the upper and lower receivers down and rearward.

Colt's made some additional changes on their own that the BATF didn't require. In 1969, Colt's wanted to use a modified M16A1 carrier to ease production costs. The original changes weren't enough for the BATF then from page 305:

On April 14, 1969, Colt updated their semi-automatic-only bolt carrier to the M16A1 configuration. Both the bolts and bolt carriers were manganese phosphate finished, with the inside of the carriers and keys chrome plated. Even though the SP1 did not have a forward assist assembly, the "Later Issue" bolt carrier came with the forward assist notches.

More modifictions were made by request of the BATF, who wanted to make the rifles more difficult to convert to full automatic. Modifications were accordingly made to the bolt carrier, firing pin, and hammer, to prevent the rifle from slam-firing should the disconnector be removed or damaged, either by intent or through malfunction. In a safety mechanism package designed and patented by Colt's Ralph Kennedy, metal was removed from the bottom of the carrier, exposing the second head of the firing pin. This functioned in conjuction with the semi-auto-only hammer with the notch cut in the front. If the disconnector should fail or be removed or disabled, the hammer would ride the bolt carrier forward, the notch in the hammer engaging the second (larger) head on the firing pin to catch the bolt carrier group and stop the rifle from firing the second shot.

Later Colt removed all the metal at the bottom rear of the carrier, but they did that on their own.

Jeff

 

[artherd]

The ATFE has jailed people over a paper clip and a shoe string. If they say not to use M16 carriers, I won't use them. Even if it is legal, the attorney fees will be much more than spending a little more on an AR15 carrier.

You know what? To heck with the ATF threatening malicious prosecution of legal acts! And to heck with that stoping me from living my life! I have both the attorneys and the time to fight them if need be.

I am also sick of threads asking for help in clarification in a lega matter being littered with subjective judgements on the matter "WELL! Harump! **I** wouldn't do it! Not that I know anything else relivant on the legality of the matter."

 

[artherd]

ATF has however opined (not sure if any courts have upheld this) that enough fire control parts to make ANY one AR-15 into a full machine gun, and posession of any other AR-15, constitutes posession of an unregistered machine gun.

Ie, you have one registered Colt AR-15 with a DIAS to make it a legal full-auto.

And then you have one unregistered unmodified Colt AR-15. And you have a spare DIAS on a shelf.

Oops, you've actually got 2 'machine guns' (ish) and one isn't registered!!!

Looking for the opinion letter now.


Not sure what ATF's position on:
1 AR-15 with one DIAS, and:
1 stock AR-15 (only, no spare DIAS on a shelf.)

 

[c_yeager]

And then you have one unregistered unmodified Colt AR-15. And you have a spare DIAS on a shelf.

IIRC an unregistered "drop in auto sear" is illegal all by itself.

The ATFE has jailed people over a paper clip and a shoe string. If they say not to use M16 carriers, I won't use them. Even if it is legal, the attorney fees will be much more than spending a little more on an AR15 carrier.

The difference is that the paper-clip and shoe string were actually used to make a rifle fire full auto, the M16 carrier doesnt. In fact the example could lend one to believe that the M16 carrier is legal. Clearly the parts themselves don't matter, it's the end function of the rifle that matters (i.e. is it a machinegun or not).

 

[shoobe01]

One of the more recent SARs had their legal guy go into this. He said everything I had previously heard and explained it pretty well, so -- without looking at the issue -- here is the issue:

Used to be, right after the NFA was passed, that an MG was an MG. Only counted if it went full-auto. So separating the gun in half or other simple things made it not, legally, an MG. And all was good. However, people used this as a loophole specifically to have an auto gun but not get it registered, so they closed that, and lots of guns with no intent got outlawed just due to some.

This sort of tinkering and loophole searching continued up to the mid 80s or so. Remember when you could go to a gun show and one guy had a table of AK auto-capable sears, BUT NOT HAMMERS. The next table over an entirely different guy just happens to have a table of AK auto-capable hammers, plus some more robust springs and such, BUT NO SEARS. Only in combination were they illegal, so it was up to individuals to make that choice.

So instead of more tinkering with specifics the ATF just finally interpreted the law as banning the ownership of /anything/ that functionally contributes to the automaticness (usually, sears, hammers, and other tripping devices to include some carriers). I am pretty sure that they still need to be combined with something, but a semi-auto receiver counts. So since I own no ARs of any sort, I could theoretically safely purchase an M16 auto group. If I had an AR-15, even one configured to not accept the parts, it would be illegal.

See, this way they generally don't have to tinker and fiddle and make the gun go auto. They can just look it up in a book and if this is a functional AR-15 and that's an auto carrier, "you have the right to remain..."

I also think they started prosecuting the dealers of these parts so that's why you see no more conversion-kit Ar-15, trigger bits, and all the notices about how to use parts kits in the ads.


All ATF guys I have spoken with are very nice and helpful. I am sure some are dicks, but so are many people at my office. Just note that it took them like 50 years to get this restrictive with MGs. They seem to -- in general, over the long view -- intepret the law only as much as needed, and change interpretation to cover loopholes. I'd say blame the law instead, but you could also blame other parts of individual administrations for not advising the bureau to be less restrictive till futher notice. Never seems to happen, though.

And I live in a functionally no-NFA state as well. So sad. Think of all the money I could contribute to the economy with just ammo purchases.

 

[ether]

Jeff White - thanks a bundle for the hard documentation....very informative.

 

[saltydog]

We''ll from what I see, ATF can pretty much get a conviction on anyone in this thread that owns any type of semi auto if they wanted to. No parts needed. From what I read in the regulations and what ATF does to get a weapon to fire full auto (even in an unsafe condition) should be of concern to anybody here. With little or no effort from your part "or" the govt's part, your firing pin can be jammed into its "forward position" The weapon will be unsafe, down right dangerous to fire, but it will be enough modification to your weapon to land you in jail, "under the law". It only needs to fire "once out of battery" and byby.....Have a nice day.

BTW, its called a fixed firing pin.

The real intent of that law was to keep people from dropping in auto sears or modifying their receivers (factory sear) -->to the real thing. Anything more than that was considered "out of line" but in this day and age?