Modification to Full Auto

[SkyDaver]

No, I'm not asking how to do it!

In the news, it's been stated that the San Bernadino terrorists had attempted to modify a S&W M&P 15 to fire full auto.

Lost somewhere in the back recesses of my brain, I thought there was an ATF regulation something like this:

If a firearm could be modified in to fire in proper full auto in less than 8 hours, by an experienced gunsmith in a fully equipped shop, the firearm was considered by the ATF to be an NFA firearm.

Proper full auto included that the firearm would stop cycling when the trigger was released. (I've heard of 1911s going full auto due to a worn/failed part, but they wouldn't stop firing. That doesn't count)

So, is my recollection anything like reality?

 

[il_10]

From http://jpfo.org/filegen-n-z/savage2.htm

"Readily restorable" is a term used in the National Firearms Act of 1934 (NFA) and the Gun Control Act of 1968 (GCA). The term was never technically defined when the laws were written or enacted. In practice, the term "readily restorable" was written into the law to forbid any firearm design that could be converted from semi-automatic to full-auto with "a quick modification." "Quick modification" can be interpreted by FTB to mean "15 minutes with simple hand tools" or "eight hours in a modern machine shop" depending on the whim of the examiner.

Eight hours in a machine shop would be nearly enough time for a skilled machinist to build an entirely new machine gun from scratch, much less convert something as simple as an AK or AR. With a fully stocked shop, that job could be knocked out in a half an hour (DIAS or lightning link), to a few hours, but ARs and AKs don't meet the ATFs definition as of now. Unfortunately, they exercise their power arbitrarily in this case. Open bolt semi mac 10s and mac 11s are illegal machine guns... unless they were manufactured before the cut off date

Also, your 1911 would be a machine gun in the eyes of the ATF as well:

“any weapon which shoots, is designed to shoot, or can be readily restored to shoot, automatically more than one shot, without manual reloading, by a single function of the
trigger. The term shall also include the frame or receiver of any such weapon, any part designed and intended solely and exclusively, or combination of parts designed and intended, for use in converting a weapon into a machinegun, and 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.”

A runaway 1911 or SKS "shoots...more than one shot... by a single function of the trigger." it doesn't have to be stoppable or well engineered; if one trigger pull gets you more than one round, the ATF view it as a title II firearm.

 

[4thPointOfContact]

Rumor is that early generations of everyone's favorite PDW could be induced to provide controllable automatic fire as well.

 

[barnbwt]

"Rumor is that early generations of everyone's favorite PDW could be induced to provide controllable automatic fire as well."
Rumor has it that people buy/sell the Gen 1 trigger packs on Gunbroker for many hundreds of dollars, thinking the ATF is none the wiser

As far as 'time for conversion,' the ATF once ruled --for ten years' time-- that a shoelace was a machinegun. A press can punch out lightning links in a fraction of a second (I'm not sure if the dies are considered 'constructive possession' or if materials are also needed, but I won't be finding out), and a quality high-speed CNC mill with good carbide tooling can turn an AR lower (or 80%) into a fully-matriculated machinegun in seconds.

Most designs of semi-auto that have full-auto counterparts have but a couple features missing and 'denied' (physically blocked by additional material left in the receiver when it is made) that differentiate them. To someone intent (!) upon an illegal conversion, they are easily defeated. The main thing the ATF is and has always been interested in, is that these features be so arranged that clear intent (!) is required to bypass them and that evidence of that bypass cannot be easily removed. Because that is what makes a case easy for them to prove in court beyond a reasonable doubt, and that is what matters to them at the end of the day.

Most likely the shooters had removed the "sear shelf" at the back of the FCG which, IIRC, allows certain designs of "lightning link" to be installed; they won't fit otherwise. In that case, the modification of the receiver is not illegal (as not all receivers are made with that shelf, even to this day), but the manufacture/possession/installation of the lightning link is. Another method would be for a true M16 auto-sear to be installed, which requires removing that shelf as well as drilling the new sear's extra pivot hole & replacing the FCG with select fire parts. Just as likely, knowing these two's aptitude for building mechanical devices (none of their pipe bombs functioned) the removal of the shelf was botched and did not result in reliable automatic fire, and the lightning link was not used (since I've not heard any reports the gun was actually in an automatic or select fire configuration)

TCB

 

[MachIVshooter]

They just didnt know what they were doing is all. 10 minutes with a drilling fixture and a M16 FCG/bolt carrier and a little tuning of sear timing and they would have been into full ammo waste territory.

As Barnbwt explained, it's not just drilling a hole, and there's no "sear timing" aspect. To go FA with an AR, you have to trip the sear. The lightning link does this by disengaging the disconnector when the BCG goes forward. With a LL, you have safe and full auto only. A proper M16 FCG has a different hammer and trigger, as well as the auto sear. In SA, it works just like an AR-15 FCG. In full auto, the disconnector is held down by the selector, and the auto sear engages another hook on the back of the hammer, which is released when the bolt trips it.

 

[yugorpk]

"Rumor is that early generations of everyone's favorite PDW could be induced to provide controllable automatic fire as well."
Rumor has it that people buy/sell the Gen 1 trigger packs on Gunbroker for many hundreds of dollars, thinking the ATF is none the wiser

As far as 'time for conversion,' the ATF once ruled --for ten years' time-- that a shoelace was a machinegun. A press can punch out lightning links in a fraction of a second (I'm not sure if the dies are considered 'constructive possession' or if materials are also needed, but I won't be finding out), and a quality high-speed CNC mill with good carbide tooling can turn an AR lower (or 80%) into a fully-matriculated machinegun in seconds.

Most designs of semi-auto that have full-auto counterparts have but a couple features missing and 'denied' (physically blocked by additional material left in the receiver when it is made) that differentiate them. To someone intent (!) upon an illegal conversion, they are easily defeated. The main thing the ATF is and has always been interested in, is that these features be so arranged that clear intent (!) is required to bypass them and that evidence of that bypass cannot be easily removed. Because that is what makes a case easy for them to prove in court beyond a reasonable doubt, and that is what matters to them at the end of the day.

Most likely the shooters had removed the "sear shelf" at the back of the FCG which, IIRC, allows certain designs of "lightning link" to be installed; they won't fit otherwise. In that case, the modification of the receiver is not illegal (as not all receivers are made with that shelf, even to this day), but the manufacture/possession/installation of the lightning link is. Another method would be for a true M16 auto-sear to be installed, which requires removing that shelf as well as drilling the new sear's extra pivot hole & replacing the FCG with select fire parts. Just as likely, knowing these two's aptitude for building mechanical devices (none of their pipe bombs functioned) the removal of the shelf was botched and did not result in reliable automatic fire, and the lightning link was not used (since I've not heard any reports the gun was actually in an automatic or select fire configuration)

TCB

Many of the modern receivers on the market are low shelf and dont require any mods. Half of mine don't. In any case a lighning link doesnt need a low shelf. Only DIAS does. Me thinks those idiots couldnt have machined their way out of a wet paper bag. Any middle school kid with an IQ over 110 could get a pipe bomb to go off.

 

[Jim K]

The "bullet button" has nothing to do with full auto fire. The CA law originally banned certain semi-auto rifles with detachable magazines. Someone pointed out that rifles like the FAL 49 have magazines that are detachable with tools but that cannot be loaded off the rifle, so the law was written to allow rifles with detachable magazines if a tool was required to detach the magazines. So someone came up with a magazine release for the AR type rifles that could not be operated just by pushing it, but required a bullet point (the tool) to release the magazine. That magazine release is the so-called "bullet button". Apparently, the people in question either installed the normal magazine release of modified the legal one to operate with a push so they could more easily change magazines. It has nothing to do with full auto fire.

Jim

 

[m0par]

It has nothing to do with full auto fire.

Tell Gregg Jarrett (of fox news) that. After the San Bernadino attack, the idiot actually claimed that:

Here's the thing; manufacturers are allowed to build them that way, with what is called a bullet button. That is to say, you take the tip of a bullet, you press a button and it turns your semiautomatic, legal weapon into an illegal assault weapon.

And this nonsense is being spread by the closest thing we have to a 2A ally in the msm.

 

[Onmilo]

Without a working auto sear you are wasting your time trying to convert an AR15 to full auto M!6 and every AR!5 lower receiver made today is machined in a manner that makes it impossible to correctly install a correctly functioning auto sear.

Good luck with those illegal modification projects.

It is my understanding that the idiots had a slide fire or bump fire type system but were not able to get it installed on the weapon.

 

[hso]

If a firearm could be modified in to fire in proper full auto in less than 8 hours, by an experienced gunsmith in a fully equipped shop, the firearm was considered by the ATF to be an NFA firearm.

No, if it fires more than one round with a squeeze of the trigger it is a "machine gun". Just that simple, no need for machine shops.

any weapon which shoots, is designed to shoot, or can be readily restored to shoot, automatically more than one shot, without manual reloading, by a single function of the trigger

***
The second post alludes to the criteria of whether a firearm is readily convertible to full auto or not, but you can build a FA in a day with a machine shop (probably several).

 

[SkyDaver]

some clarification

hso kindly unlocked the thread so I could post a clarification:

I absolutely was NOT asking how to do this.

My purpose was to have factual information I could use to rebut claims that it was easy to convert a semi-automatic AR to full-auto

Thanks to all that responded.

 

[yugorpk]

You can ask how to convert to full auto and we can tell you. Perfectly legal to talk about this stuff. Its even legal to actually do the conversion if you get an 02/07 license. Ive had one and its fun for a few years until it gets out of your system.

And yes, despite what I have read in stunned disbelief here it is extremely easy to convert AR-15's to full auto operation . Many semiauto's can easily be converted to full auto with a few easily available parts and a very minimum of machine shop skill.

 

[rcmodel]

That's all well & good if you have a license to build dealer sample machine guns.

But in the interest of keeping new members, and visitors out of a Federal Slammer, bunking with Bubba the bandit?

One cannot build or convert a firearm to full auto, pay the $200 tax, and regester it since 1986.

Just so everyone is on the same page and doesn't get any wild ideas from this thread!

rc

 

[USAF_Vet]

Some guns are fairly easy to convert to FA. I've even seen manuals for sale on how to accomplish this task. The SKS is one of them. An antique shop nearby has several of them. The information itself is not illegal. You can download the plans for a Luty SMG online. Or a STEN. Only actually building one is illegal. Can't stop the signal, Mal.

Other guns are much more difficult, if not impossible, to convert.

If one wanted to build a FA gun legally, there are ways to do it, that have been covered.



In any event, I haven't heard of a reputable media outlet that actually has proof the San Bernardino shooters attempted to convert their ARs to FA. I heard the idjits on Fox news rant about the bullet button, and how it "failed", but haven't seen anything that showed the internal components like a modified receiver or fire control group. Are we even certain that they tried a full auto conversion?