www-2.cs.cmu.edu/afs/cs/user/wbardwel/public/nfalist/atf_letter35.txt

Dano,

That letter seems to contradict your position, not support it.  The letter clearly states that in order for it to be considered a machine gun, you must possess all the component parts that would allow it to fire in auto.  I don't believe the carrier, by itself, is considered such.  Possession of all the M16 fire control parts would perhaps be a different story.  The only exception to this is an autosear, which has been ruled to be a machinegun in and of itself.

If your argument that possession of an m16 carrier along with a toothpick/matchstick/etc qualifies as a machinegun, then by the same reasoning, owning a semiauto AK and a shoelace is as well.  As for creating a slamfire situation, then so is owning anything with a freefloating firing pin and an handful of dirt to gum it up.

Rocko

Originally Posted By rocko: Dano, That letter seems to contradict your position, not support it.  The letter clearly states that in order for it to be considered a machine gun, you must possess all the component parts that would allow it to fire in auto.  I don't believe the carrier, by itself, is considered such.  Possession of all the M16 fire control parts would perhaps be a different story.  The only exception to this is an autosear, which has been ruled to be a machinegun in and of itself. If your argument that possession of an m16 carrier along with a toothpick/matchstick/etc qualifies as a machinegun, then by the same reasoning, owning a semiauto AK and a shoelace is as well.  As for creating a slamfire situation, then so is owning anything with a freefloating firing pin and an handful of dirt to gum it up. Rocko

I concur!

OK guys. I give up!!!!!!

Since It hasn't yet dawned on you guys that the hooded carrier is the key to get the rifle to fire full auto.  And, the fact that the BAFT will convict on "Intent to create a machine gun" by just having a conversion part, I hope that you stand by your convictions and help out any person that gets arrested for having a M-16 carrier in his Semi auto rifle.

Granted that the BATF will not go after someone for just this reason, but If someone gives them any other reason(pisses them off), I insure you that this will be one of the items that will be prosecuted. Granted that BATF may not win the case. But, they really don't need to since the legal fee's alone, will probably bankrupt the person.

Since it seems to be the census of this group to uphold that a M-16 carrier, can not be solely used to convert a weapon to full auto, Then when the time comes, I hope your convictions are backed up by the legal funding that will need to used to fight this case.
Dano

Originally Posted By Dano523: OK guys. I give up!!!!!! Since It hasn't yet dawned on you guys that the hooded carrier is the key to get the rifle to fire full auto.  And, the fact that the BAFT will convict on "Intent to create a machine gun" by just having a conversion part, I hope that you stand by your convictions and help out any person that gets arrested for having a M-16 carrier in his Semi auto rifle. Granted that the BATF will not go after someone for just this reason, but If someone gives them any other reason(pisses them off), I insure you that this will be one of the items that will be prosecuted. Granted that BATF may not win the case. But, they really don't need to since the legal fee's alone, will probably bankrupt the person. Since it seems to be the census of this group to uphold that a M-16 carrier, can not be solely used to convert a weapon to full auto, Then when the time comes, I hope your convictions are backed up by the legal funding that will need to used to fight this case. Dano

And a happy new year to you too!

Well said Steve. Thanks for bringing a level head and excellent legal knowledge and experience to the forum.

On a related question, how about an M16 carrier that has been neutered to look like an AR carrier?

Originally Posted By entropy: On a related question, how about an M16 carrier that has been neutered to look like an AR carrier?

Nothing wrong with it. Colt has milled 16 carriers and put them in civilian guns for years--mill marks on them are obvious.

Please no more screaming and cussing in this forum. Jeeze,that's just about enough. Talk like that and get banned I say...Everybody sure is getting wraped around the axel about these silly M-16 parts questions!

Besides.... if you are gonna troll.... troll right!  Like this:

And never forget this:  We still live in a country where you are tried by a JURY!  Yes they can arrest you because they "can make it fore two conscecutive shots' afte fiddling with and abusing it for hours ... but that will not convince the average JURY of your guilt.  This is not Nazi Germany YET anyway!  We always FORGET avout the JURY when we are having these legal disscussions.  Remember if it sounds ridiculous to all of us here then it will to a jury too. BUT having said that , even though they WILL NOT get their conviction, they WILL make your life HELL if they disire to do wo.  Unless of course you are rather wealthy or carry good legal insurance.  The legal insurance would seem to be a VERY good thing for someone in these types of shooting pastimes like many of us here are ... I guess that is why when it became available at work I grabbed it!


someone replied "Until and unless ATF demonstrates to a court, as part of a prosecution, that your AR fires more than one shot with a single pull/release of the trigger, you're within the law to install any parts in your AR-15 or clone that you like."

Contrary to the myth, there were never any actual M16 bolt carriers used in assembling the early Colt AR-15s. I have SN 00694, from 1964, and it does not have an M16 bolt carrier, nor is it chromed (the bolt itself is chromed, however).

Over the years there seem to have been three distinct configurations of bolt carriers used by Colt. First they used one that was very similar to the M16 unit, but if you compare them the underside is milled out a bit more than the M16 unit (my '694 has one of these). Later, in the 1970s I guess, they milled it out even more, leaving only a small band of material at the bottom rear of the carrier. Then, in more PC times (90s?) they just milled away all the metal at the bottom rear of the carrier. This seems to function fine, but looks kind of wrong. So, if you're used to the latter two types, the old carriers look at first glance as if they're M16 parts, but they're not.

Now, having said that, the non-Colt builders have used everything under the sun, including at times surplus M16 parts.

WRT using an M16 carrier, I see a lot of people doing that, especially competitive shooters. We asked our local ATF guys who shoot at our range, and they said they could care less, they're not worried about the good guys. And since 9/11, they really don't care, and wouldn't have the manpower to go around checking this stuff even if they did. So, as somebody already said, do what you're comfortable with as long as your gun only gives one bang per pull.

FYI - DPMS sells slick-side AR-15 bolt carriers, in both chrome and park'd finish.

Originally Posted By Booth: FYI - DPMS sells slick-side AR-15 bolt carriers, in both chrome and park'd finish.

They Do?

I've been looking all over for a slick side parkerized carrier. Do you have a link? Thanks a ton!

I have to admit I was previously misinformed as well.

Question....  What is the advantage of a heavier BC?  It does not add much weight to the rifle, all I can think of is it would slow down the cycle time.  What for?

Just a BTT...

Seem this question is being asked again, and i thought i'd brign the answer back up.

                  DEPARTMENT OF THE TREASURY
            BUREAU OF ALCOHOL, TOBACCO AND FIREARMS
                     WASHINGTON, DC 20226

                        MAR 25 1999                   903050:CHB
                                                      3311


Dear Mr. :

This refers to your letter in which you asked about possession of
spare M-16 machinegun parts by a person who possesses a registered
M-16 and a semiautomatic AR-15 rifle.

Any weapon which shoots automatically more than one shot, without
manual reloading, by a single function of the trigger meets the
definition of a machinegun in section 5845(b) of the National
Firearms Act (NFA).  An AR-15 rifle, which is assembled with
certain M-16 machinegun fire control components, and which is
capable of shooting automatically is a machinegun as defined.

The definition of machinegun in section 5845(b) also includes any
combination of parts from which a machinegun can be assembled if
such parts are in the possession or under the control of a person.
Thus, an AR-15 rifle possessed with separate M-16 machinegun
components can meet the definition of a machinegun, if the rifle
shoots automatically when the components are installed.

The fact that a person lawfully possesses a registered NFA firearm
does not grant authorization to possess additional non-registered
firearms.  A person who possesses a registered M-16 machinegun and
a semiautomatic AR-15 rifle and a separate quantity of M-16
machinegun components could be in possession of two machineguns.

                             - 2 -

Mr.

We would advise any person who possesses an AR-15 rifle not to
possess M-16 fire control component.  If a person possessed only
the M-16 machinegun and spare M-16 fire control components for that
machinegun, the person would possess only one machinegun.

We trust that the foregoing has been responsive to your inquiry.
If you have further questions concerning this matter, please
contact us.

                       Sincerely yours,


                      Edward M. Owen, Jr.
               Chief, Firearms Technology Branch

                  DEPARTMENT OF THE TREASURY
            BUREAU OF ALCOHOL, TOBACCO AND FIREARMS
                     WASHINGTON, DC 20226

                          MAR 29 2000

                                                      903050:GKD
                                                      3311

Dear Mr. :

This refers to your letter of January 22, 1999, requesting
information on the legality of possessing a registered full auto
AR15 and also possessing one or more semiautomatic pre-1994
assembled AR15 rifles.  You appended a number of specific questions
relating to this subject which will be answered in the order
received.

1.   Is it legal to own both?

There are no provisions under the Gun Control Act of 1968 (GCA) or
the National Firearms Act (NFA) that prevent an individual from
possessing an AR15 registered machinegun and one or more
semiautomatic AR15 rifles at the same time.

2.   If legal to own both, which spare parts for the registered gun
can you also own?

Any weapon which shoots automatically more than one shot, without
manual reloading, by a single function of the trigger meets the
definition of a machinegun in section 5845(b) of the NFA.  An AR15
rifle which is assembled with certain M16 machinegun fire control
components, and which is capable of shooting automatically is a
machinegun as defined.

The definition of a machinegun in section 5845(b) also includes any
combination of parts from which a machinegun can be assembled if
such parts are in the possession or under the control of a person.
Thus, an AR15 rifle possessed with separate M16 machinegun
components can meet the definition of a machinegun, if the rifle
shoots automatically when the components are installed.

The fact that a person lawfully possesses a registered NFA firearm
does not grant authorization to possess additional non-registered
firearms.  A person who possesses a registered M16 machinegun and
a semiautomatic AR15 and a separate quantity of M16 machinegun
components could be in possession of two machineguns.

We advise any person who possesses an AR15 rifle not to possess M16
fire control components (trigger, hammer, disconnector, selector,
and bolt carrier).  If a person possessed only the M16 machinegun
and spare M16 fire control components for that machinegun, the
person would possess only one machinegun.

3. Is it legal to use the upper receiver off of the semi-auto AR's
on the registered AR if they are different lengths and calibers
than listed on the Form 4's?

Before changing the caliber of a registered machinegun you should
notify the NFA Branch in writing of the proposed change.

4. Can you have several short barrel uppers (less than 16 inches)
for the registered AR and still own semi-auto AR's?

The definition of a firearm in section 5845 of the NFA includes a
rifle having a barrel or barrels of less than 16 inches in length.
An individual possessing more than one short (less than 16 inches)
barreled upper receiver for a registered AR15 machinegun along with
one or more semiautomatic AR15 rifles would have under their
possession of control an unregistered short barreled rifle, a
violation of the NFA.

5. If you change the barrel length or caliber do I need to notify
your office if the change is not a permanent one?

This question was answered under Question 3.

We trust that the foregoing has been responsive to your inquiry.
If we can be of any further assistance, please contact us.


                       Sincerely yours,


                           [signed]
                      Edward M. Owen, Jr.
               Chief, Firearms Technology Branch

Originally Posted By Steve-in-VA: Originally Posted By m60308nato: Any m16 parts in an ar15 rifle is illegal and makes it a machine gun, weather it fires more then one shot per trigger pull is irrelevant. . Bullshit.

I second that bullshit...
What the hell are you people talking about? Read the damn laws!

"We advise any person who possesses an AR15 rifle not to possess M16
fire control components (trigger, hammer, disconnector, selector,
and bolt carrier). If a person possessed only the M16 machinegun
and spare M16 fire control components for that machinegun, the
person would possess only one machinegun."

Key word is ADVISE. They ADVISE you do not possess an AR-15 and M16 parts. They do not say it is ILLEGAL to possess an ARand M16 parts, they ADVICE you don't.

I ADVISE you don't ram small furry animals into your anus. Does that mean it's against any law? No. It just means i suggest against doing so.

ad·vise    ( v.)

To offer advice to; counsel.
To recommend; suggest: advised patience.

ad·vise ( v.)

To offer advice to; counsel.
To recommend; suggest: advised patience.
To prevent firearm confiscation.
To prevent undue legal expense.
To prevent red marks on wrists from handcuffs.

I believe that Bushmaster puts that language in their catalog for CYA purposes. In the event of a misguided lawsuit, like the one underway, this may help their case.

All of the Armalites I've owned in the past had M16 triggers (original variety). Every single one of them accepts the M16 disconnector. This also goes for the Armalite fire control set in the green plastic case.

Finally, I believe the hysteria of M16 parts was helped by the original board owner who I think is Ed, Jr. He had posted an article on how to identify M16 parts and inclusion of any one such part is a machine gun. Or, something of that sort. This was circa 1998 or 1999.

I believe that Bushmaster puts that language in their catalog for CYA purposes. In the event of a misguided lawsuit, like the one underway, this may help their case.

All of the Armalites I've owned in the past had M16 triggers (original variety). Every single one of them accepts the M16 disconnector. This also goes for the Armalite fire control set in the green plastic case.

Finally, I believe the hysteria of M16 parts was helped by the original board owner who I think is Ed, Jr. He had posted an article on how to identify M16 parts and inclusion of any one such part is a machine gun. Or, something of that sort. This was circa 1998 or 1999.

I believe that Bushmaster puts that language in their catalog for CYA purposes. In the event of a misguided lawsuit, like the one underway, this may help their case.

All of the Armalites I've owned in the past had M16 triggers (original variety). Every single one of them accepts the M16 disconnector. This also goes for the Armalite fire control set in the green plastic case.

Finally, I believe the hysteria of M16 parts was helped by the original board owner who I think is Ed, Jr. He had posted an article on how to identify M16 parts and inclusion of any one such part is a machine gun. Or, something of that sort. This was circa 1998 or 1999.

Oops, three round burst... I guess BATF will come looking for me due to those M16 keyboard parts. :)

As much as I hate to hijack this thread, I had a question and all the people I want to ask are here.

A well-known AR parts supplier (I'm not mentioning any names) sells what's called an "Altered Safety Selector" which is, as I understand it, an M16 selector with the disconnector camming surface milled off.  Completetly.  Flat.  So that the selector will go safe, fire, fire...

That's right...the thing goes to all 3 positions, but there is, physically and functionally, absolutely no difference between position 2 and position 3...They're both Semi Auto.

This company sells this item both as a single replacement part, AND as the safety/selector in their AR Parts Kit.

So I have to ask.  Given the information here, since it's now an AR part...and the "bad juju" part of it has been milled away, is it illegal to put in a rifle?

1) In its current configuration, it cannot and will not allow the rifle to fire full-auto, either with the rest of a full set of M16 parts or by itself.  It lacks the proper camming surface to rotate the disconnector.

2) In its current configuration, I don't see how such a part could be reactivated without a lot of careful welding and remachining, which would be more time-consuming and non-cost-effective than just buying a real M16 selector in the first place.

3) The part was "at one time" an M16 part.

So, what do you say?  Can I use this thing or should I throw it out and get a "proper" AR part?

I personally kinda like the idea of the selector going to the 3rd position, sort of a "Hah" factor, especially since it does nothing special.

Panz

Panzer,

  MY guess would be, as Steve points out, if the parts do not allow the weapon to fire in full auto, it would be perfectly legal.

I tihnk this would be cool as hell to freak my friends out with the 3rd position. Would you mind PM-ing me the address of this item?

Done.

Panz

I'll ask this question, if it is illegal to have an M16 carrier in an AR15 then every Colt green label 9MM would be illegal as they have the SA/FA bolt carrier, but yet they are only capable of firing in semi as the rest of the parts are not installed to make it a machine gun.

There has been a lot out there, and I have always been given to understand, that the collection of M16 parts constitutes illegal possession of a machine gun.  It may very well be that is not technically the letter of the law.  As many have found out the hard way, the law is what ATF says it is.  Sure, you can go to court, etc., etc.  Best bet is to not give them any reason to find something to make a case.

Originally Posted By rjroberts: There has been a lot out there, and I have always been given to understand, that the collection of M16 parts constitutes illegal possession of a machine gun.  It may very well be that is not technically the letter of the law.  As many have found out the hard way, the law is what ATF says it is.  Sure, you can go to court, etc., etc.  Best bet is to not give them any reason to find something to make a case.

Sure... if you have ALL of the M16 parts, you are prolly in possession of an unregistered MG. But just one part? I do not know of JUST ONE m16 part that can make a rifle fire more that one round per operation of the trigger. Hell, even an auto sear still needs all the other M16 parts. if you take out one part, the rest are useless.

Originally Posted By arjohnson: I'll ask this question, if it is illegal to have an M16 carrier in an AR15 then every Colt green label 9MM would be illegal as they have the SA/FA bolt carrier, but yet they are only capable of firing in semi as the rest of the parts are not installed to make it a machine gun.

Huh, Colt makes a semi-auto only 9mm bolt.

Every Colt Factory 9mm carbine I've seen had the semi version.  Both Green and Blue.  

However, that's not to say Colt never shipped one with a FA bolt.  Their latest products have been lacking.  

Some colt factory 9mm 16" uppers were shipped with the FA bolt.  



Righteous Kill,

Originally Posted By NAM: Originally Posted By rjroberts: There has been a lot out there, and I have always been given to understand, that the collection of M16 parts constitutes illegal possession of a machine gun.  It may very well be that is not technically the letter of the law.  As many have found out the hard way, the law is what ATF says it is.  Sure, you can go to court, etc., etc.  Best bet is to not give them any reason to find something to make a case. Sure... if you have ALL of the M16 parts, you are prolly in possession of an unregistered MG. But just one part? I do not know of JUST ONE m16 part that can make a rifle fire more that one round per operation of the trigger. Hell, even an auto sear still needs all the other M16 parts. if you take out one part, the rest are useless.

The start of the thread was the bolt, and then the discussion grew.  To address your issue, one acronym/abbreviation:  DIAS .  That's enough, though you would be correct in saying it wouldn't be the whole set.  Nevertheless....what's that I hear in the distance, a slight banging sound, sounds like the stamping of metal, or is it making shoes (I don't know about now, but years ago, military low-quarter shoes were made in Leavenworth)?

Originally Posted By rjroberts: The start of the thread was the bolt, and then the discussion grew.  To address your issue, one acronym/abbreviation:  DIAS .  That's enough, though you would be correct in saying it wouldn't be the whole set.  Nevertheless....what's that I hear in the distance, a slight banging sound, sounds like the stamping of metal, or is it making shoes (I don't know about now, but years ago, military low-quarter shoes were made in Leavenworth)?

ahh...but a DIAS itself if concidered a machinegun. possession of that part and an AR constitues an illegal unregistered machinegun. that's a DIAS or LL. it is perfectly legal to have as many autosears as you want. The point i was trying to make, is that you really need not worry about a part or two. as long as the rifle does not fire FA, you are ok ACCORDING TO THE LAW. Yes, they may give you some shit. But the law is very clear. And yes, if you have ll necessary partsw to convert your AR to full atuo, then you may also have a problem. But, a bolt carrier alone does not permit full auto firing of a weapon. THerefore, it can be correctly said that it is perfectly legal to have an M16 carrier in an AR15.

Note: i am not a lawyer, i do not claim to be one. However, i did stay in a Holiday in once...

This is a great thread and I agree that it takes more than a part or two to make an AR-15 into an M-16....

The manufacturers are very conservative in their publishing of legal advise because they need to worry that somebody without being scared, could start putting M-16 parts in their gun!  Then, when the fool get's enough there for a full-auto, they might well try to come back to the manufacturer and sue them!

This applies to many of the ATF regulations that are often mis-quoted including what is an Collapsable stock & How can you fix one to be post-ban compliant, What is a Detachable Magazine & what would be required to make an AR Magazine non-detachable, What is the legality of a forward grip on a pistol, Can a SBR be used without a stock (Pistol Style), Can a SBR be configured like an AOW.....

These are all grey areas and you really need to read and understand the law!  We could argue about each of the new examples as hard as we just did about M-16 parts in an AR-15 and if you go to the ATF without a well defined description of what you want you may or may not get a clear answer.

Some people, just lack the education to bother trying to read the regulations and think about what the law really says!  It's a shame!

I think I finally understand. You can wear two machine guns (DIAS) as cufflinks if you don't own an AR-15.  If you get an AR-15 for your birthday, the cufflinks must go, even though you do not own the M-16 parts to make it work.

I know you are just kidding, but....

That is only the case with the pre-81 DIAS which are chunks of metal.... Any DIAS made after '81 is defined to be a machine gun by the LAW regardless of an AR-15 or any M-16 parts to make it work!

Okay, if I understand this correctly (doubtable?):

-Having enough parts in your gun to make it FA is illegal.

-Dropping an M16 bolt carrier into the gun, does not in and of itself make the gun FA

-Removing the disconnector while the M16 bolt carrier is in the gun makes it FA

-Once the M16 bolt carrier is in the gun, you don't need any additional parts to make the gun FA. You need to take a part away (disconnector).

Question: Doesn't that constitue having all of the parts installed thar are required to make the gun FA?

Like it was said though, technically, all that you would need to make an AR-15 FA would be some dirt in the firing pin channel. So, what's up with all of this?

Originally Posted By Johnphin: Okay, if I understand this correctly (doubtable?): -Having enough parts in your gun to make it FA is illegal. -Dropping an M16 bolt carrier into the gun, does not in and of itself make the gun FA -Removing the disconnector while the M16 bolt carrier is in the gun makes it FA -Once the M16 bolt carrier is in the gun, you don't need any additional parts to make the gun FA. You need to take a part away (disconnector). Question: Doesn't that constitue having all of the parts installed thar are required to make the gun FA? Like it was said though, technically, all that you would need to make an AR-15 FA would be some dirt in the firing pin channel. So, what's up with all of this?

Let me put it this way....do you have a "friend" who ever tried this?

Under most circumstances, standard ammo will not slam fire. Removing the disconnector, while using an M16 carrier, will not work. Typically, there isn't enough energy to hit the firing pin hard enough.

Now, yes, im some cases this may very well work. IT is quite hazardous, but it is theoretically possible. But very, very rare.  

And if the ATF is of the stance that an M16 type carrier, with the shrouded firing pin, does constitute FA, why have they not gone after RRA's AR-15 carrier? IT has the ar15 style sear trip, but the M16 shrouded firing pin.

Personally, i see no legal wrong in using an M16 carrier with AR15 parts. IF you are worried about slam firing, or want extra insurance, use a firing pin spring.

Originally Posted By NAM: Originally Posted By Johnphin: Okay, if I understand this correctly (doubtable?): -Having enough parts in your gun to make it FA is illegal. -Dropping an M16 bolt carrier into the gun, does not in and of itself make the gun FA -Removing the disconnector while the M16 bolt carrier is in the gun makes it FA -Once the M16 bolt carrier is in the gun, you don't need any additional parts to make the gun FA. You need to take a part away (disconnector). Question: Doesn't that constitue having all of the parts installed thar are required to make the gun FA? Like it was said though, technically, all that you would need to make an AR-15 FA would be some dirt in the firing pin channel. So, what's up with all of this? Let me put it this way....do you have a "friend" who ever tried this? Under most circumstances, standard ammo will not slam fire. Removing the disconnector, while using an M16 carrier, will not work. Typically, there isn't enough energy to hit the firing pin hard enough. Now, yes, im some cases this may very well work. IT is quite hazardous, but it is theoretically possible. But very, very rare.   And if the ATF is of the stance that an M16 type carrier, with the shrouded firing pin, does constitute FA, why have they not gone after RRA's AR-15 carrier? IT has the ar15 style sear trip, but the M16 shrouded firing pin. Personally, i see no legal wrong in using an M16 carrier with AR15 parts. IF you are worried about slam firing, or want extra insurance, use a firing pin spring.

Okay, cool. That answers my question. Now, about this RRA thing...That's who made my upper! I didn't know I had a special upper! Seriously though, what's the information on the firing pin spring? How do you go about getting one and installing it? Will it work in the standard bolt? Thanks!

(BTW, no, I didn't have a "friend" try that. I just got that info from reading this thread)

i have never seen a firing pin spring in a .223 setup. I do, however, own an OLY .45 ACP upper. Because of the hotter pistol primers, it's much more possible for a slam fire to occur. Because of this, they use a firing pin spring. All it is, is a spring that slides on the firing pin. It pushes against the collar on the firing pin, and keeps the firing pin pushed bach. A standard firing pin is free to slide around.

As for the RRA, the bolt carrier is the only different part. A typical AR carrier has part of the metal underneath the firing pin ground away, exposing the firing pin collar. If the disconnector is removed, the hammer will snag on the firing pin because if this. It's an added saftey measure, i beleive started by Colt.

IF you pull the trigger with the bolt half way forward, the RRA will function. The standard AR15 carrier will hang up, and not allow the action to close.

IF you do a search, there's pics of the different carriers on here somewhere...

FYI: I own AR-15 SP-1 serial number 00694 from early 1964 and it contains no M16 parts whatsoever. The bolt is chromed, but the carrier is parkerized.
I have had a couple of other early guns, one in the 01xxx range and another one from 1966 and it is the same, except that the bolt isn't chromed on the '66 gun.

...Straight from the Peoples Alcohol Tobaco and Firearms Bureau...

In order to avoid violations of the NFA, M16 hammers, triggers, disconnectors, selectors and bolt carriers must not be used in assembly of AR-15 type semiautomatic rifles, unless the M16 parts have been modified to AR-15 Model SP1 configuration. Any AR-15 type rifles which have been assembled with M16 internal components should have those parts removed and replaced with AR-15 Model SP1 type parts which are available commercially. The M16 components also may be modified to AR-15 Model SP1 configuration.

End of story.

http://www.atf.treas.gov/pub/fire-explo_pub/complete.htm
About 4/5 of the way down.