I have saw this several times on sites talking about legalities of a brace, and other sites have mention it, but only one actually said what it was, but no legal document to back it up.
It was said that 13.5 inches is about max, and that over that gets into no mans land. Mine is way shorter than that, and have no desire to go that long.
So is this 13.5 length a standard, or just someones best guess?

At the moment, that is a statement attributed to someone at the ATF Tech Branch.  It would basiclly serve as their opinion on the matter and would require a "test case" to make it into a judicial standard by which it could be called legal/illegal at a hard limit.

Attached File

Thanks for the reply. Since it was someones opinion, I guess it could go either way, depending on if the officer was having a good or bad day.

There are several levels of regulations and guidance that constitute  and carry the force of law.  

Statute - this is the law as written.

Regulations - The statute is passed to the cognizant executive branch agency to develop regulations.   These regulations further interpret and describe what is in statute, but must be consistent with the intent of congress in passing the statute ( and some times agencies get it wrong - sometimes intentionally, other times just through incompetence and a lack of understanding of the nuances and/or practical realities of the issues.   Any substantive changes in regulations are supposed to be published for public comment before they are adopted.

Regulatory Guidance - these are formal documents that provide additional guidance or definition, and they are often also issued for public comment if they are substantive in nature.

Sub-Regulatory Guidance -  This consists of specific guidance on specific issues - such as ATF response letters to questions.   They apply only to the specific issue at hand.

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The level of clearance on sub regulatory guidance is not as thorough and it does not go out for public comment so some of the mistakes made are spectacular.   The whole Sig brace issue is a prime example.   Shouldering a Sig brace equipped pistol was determined to be legal based on a collection of very narrow legal interpretations, made by attorneys, largely in the absence of common sense.   The end result was a huge number of letters from people asking "really?" - apparently because they were too stupid to just see it for what it was - a very fortunate error in there favor.   However, since they effectively made the error so obvious and egregious, ATF had to issue revised guidance.  

ATF could have simply said "On further consideration and in light of the magnitude of responses suggesting this might be a problem, we've determined that our previous guidance was in error.  We've further determined that it looks like an SBR, is shouldered like and SBR and functions like an SBR, then it's an SBR and consequently the Sig Brace is a stock that changes an AR-15 pistol into SBR."  

However, ATF again resorted to narrow legal distinctions and decided that use of the object defines the object.  Thus they determined that when an AR-15 with a Sig brace is shouldered it is no longer being used as designed, made or intended, and becomes an unregistered SBR.  Sig used the example that using a can of corn as a hammer, must therefore make a can of corn a hammer, when they pointed out the absurdity of the ATF argument.  

Another more alarming example of where this reasoning runs off the rails is in the ATF's definition of pistol:

"The term “Pistol” means a weapon originally designed, made, and intended to fire a projectile (bullet) from one or more barrels when held in one hand, and having:
•a chamber(s) as an integral part(s) of, or permanently aligned with, the bore(s);
•and a short stock designed to be gripped by one hand at an angle to and extending below the line of the bore(s).

So if we apply the ATF argument that "use can re-define the weapon", and I shoot my 1911 (one of the weapons ATF uses on their website to define "pistol") with two hands, I'm now using it other than it was designed, made and intended - per the ATF pistol definition.  

The moral here is that if the ATF can screw up sub regulatory guidance that is subject to some level of internal clearance, then an ATF field agent can most certainly say something in error - and unlike a written letter, that spoken word is of zero use in a legal defense, particularly when it becomes hearsay when repeated by the person who supposedly heard it from the ATF agent.  

The opinion of an ATF agent is just that.  It's an opinion, and does not have the force of law.   It's not smart to ignore an ATF agents opinion, particularly when he or she is telling you something is illegal, but more importantly, you don't want to take that opinion as permission to do something that conflicts with the documents above that do in fact have the force of law.   The "but the ATF agent said..." defense isn't a good one in criminal court, as all the prosecution has to demonstrate is that the agent was wrong.
 
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One other thing to consider is that some laws are not actively enforced as primary offenses.  For example,  there have not been many (if any) cases of individuals being prosecuted for shouldering a wrist brace or cheek rest equipped AR-15 pistol.  That's in part because:

1) the hole shit show described above and ATF's seriously flawed reasoning.
2) the distinction between using a saddle as a cheek rest and moving back some fraction of an inch so that it contacts the shoulder is pretty small, difficult to definitively observe from most angles, and thus is difficult to enforce and successfully prosecute (although an unsuccessful prosecution will still cost you at least 5 figures in legal bills; and  
3) It's also a victimless crime, so not too many people are demanding it be rigidly enforced.  If AR-15 pistols with saddles, braces, etc, start showing up at crime scenes in substantial numbers, or are just perceived by the public or politicians as being used in crimes, then that will change.

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Where a weapons violation of any type will get used in a prosecution is to increase the potential prison sentence, in order to get the accused to either plea bargain on the primary crime that was committed, and/or roll over and inform on someone else.   If you're looking at 10 years in federal prison for a weapons violation, accepting a plea bargain for 5 years on the armed robbery starts looking like a good deal.

Length of pull relates to how the stock is shouldered. An AR pistol cannot legally have a stock.

Don't forget that if the intention is to use it like a stock to circumvent the law then that is what is prosecutable. Nobody has written or said they won't. What the ATF decides today may be rescinded tomorrow and AR pistols are the clearest examples of that practice. At one time the ATF permitted a CAR stock pinned at the shortest length, rescinded that, allowed the Brace, rescinded that, and now seem to state they won't prosecute.

Unless you intended to circumvent the law.

Stay tuned for next months reinterpretation of the reinterpretation of an Agency's regulatory interpretation.

Learn to shoot an AR pistol with no shouldering at all and you will be twice the marksman.

I outfit my pistols with buffer tube alone, without any stock, which ATF states does not prohibited from being shoulder fired with the receiver extension alone against the shoulder....it is shoot able without any gray area...I get nose to charging handle with the KAK reinforced tube designed for the SiG brace, just without the brace... a LAW folding adapter and pistol buffer tube is about 3/8" shorter, and still works.... I carry an archived letter stating the tube alone is not prohibited.... YMMV

http://shortbarrelshepherd.com/atf-letter-on-shoulder-firing-an-ar-pistol/

Thanks for an excellent informative post and reply.  In the "pistol" definition you show, it states "intended to fire from one hand" and "designed to be gripped by one hand" are some of the basis for a weapon being defined as a pistol.  Fortunately it does not state that it MUST be used one handed, which I believe is where its OK to use 2 hands, cheek or forearm.  

I have always been a firearms enthusiast but until fairly recently I knew little to nothing about AR pistols.  When I was in law enforcement if I had come across an AR pistol that looked like many on here do I would automatically assume it to be a SBR or illegally converted rifle.  This is my fear with the AR pistol as they really do not fit the pistol definition all that well and most in law enforcement will not know the difference.  I carry the Shockwave ATF ruling letter in my pistol grip, just in case.

I agree with you - and that was the glaring inconsistency in the ATF's "use = re-design of the weapon" interpretation.  You'll note their most recent letter (4-25-17) adds some clarification:

"If, however, the shooter/possessor takes affirmative steps to configure the devices for use as a shoulder-stock--for example... removing the arm-strap, or otherwise undermining its ability to be used as a brace - AND THEN shoots the firearm from the shoulder using the accessory as a shoulder stock, that person has redesigned the firearm for purposes of the NFA."

That's an important distinction as it moves away from simply saying "if you shoulder it like an SBR, it must be an SBR" to saying "you have to take steps to modify or reconfigure it in some way that undermines its use as a brace or improves it's performance as a stock, AND THEN shoulder it and shoot it  for it to be re-designed to become an SBR.

It means in simple terms that simply firing an AR-15 pistol with a wrist brace from the shoulder does not result in it becoming an SBR.  You have to install it and modify it with the intent to utilize it as a stock, then shoot it and fire it for it to be a violation.

I also plan to keep a copy of this most recent ATF letter handy.

Whoever this unnamed agent relegated to switchboard duty was, if he really claimed any of that, he's an idiot too.

"Length of pull" only has meaning within context of using a rifle stock -- there is no ATF interpretation of the law where one "length of pull" could be legal on a pistol but a longer one would not be.
Plus there are plenty of rifles out there with 12-13" LOP, so postulating 13.5" as some sort of danger zone is doubly idiotic.

- OS

Re: the issue of "two handed use" of a pistol - it's largely an internet argument of no merit. Every LE agency and almost all of the DOD teaches two handed use of the pistol - SIG, Beretta, Glock, etc. To "outlaw" two handed use would mean outlawing the most common practice of shooting tactically to return to - what? Olympic style?

If it's a "pistol" then the regulation has to fit across the board. Even the ATF shoot their pistols with a two handed grip. Saying it's "AR" makes no difference. It's a good example of how some go overboard on reading the regulations making something out of nothing. What the ATF has to live with is barrel lengths and what constitutes a vertical forward grip, and they got backed into that perspective due to regulatory interpretation a long time ago. All it takes is a 45 degree variation from vertical - it's still a front grip.

That is the logic that forced the ATF to make their latest (April 25, 2017) clarification.  Their previous interpretation, if applied to all pistols, would mean that shooting a 1911  - one of the pistol examples used on their website to illustrate the key features/definition of "pistol" - with 2 hands would be mis-using the intended grip and thus result in it being redesigned to no longer be a pistol.

The fact that everyone except Bullseye competitors shoots them that way - including LEOs everywhere - made that an insurmountable problem.

As a practical matter all the LEOs I knew and associated with who had AR-15 pistols with braces just went ahead and shouldered them.  Most were smart enough not to advertise it, but as a practical matter no one changed their behavior when ATF changed its initial ruling.  It was both ineffective, and virtually unenforceable.

The issue with the shockwave is the technical branch does not give out opinions over the phone.

They had a write up over it on the web somewhere and it is just hearsay until there is a ATF letter. SB tactical is the only brace manufacturer that has a letter saying their product was able to be used that way.

http://www.thefirearmblog.com/blog/2017/05/15/psa-critical-analysis-shouldering-brace/