[JustinJ]

I would like to permanently install a Yankee Hill Phantom Quick Disconnect Flash hider to a 14.5 barrel. Is soldering it considered permanent? What methods are acceptable to the ATF? Also, is there an ATF letter outlining what is allowed?

[TexasRifleman]

Permanent methods of attachment include full-fusion gas or electric steel-seam welding, high-temperature (1100°F) silver
soldering, or blind pinning with the pin head welded over.

http://www.atf.gov/publications/download/p/atf-p-5320-8/atf-p-5320-8-chapter-2.pdf

[rjrivero]

Texas Rifleman,

I have looked but couldn't find this particular piece of information: Is there anywhere in the ATF guidelines that says a muzzle device needs to be made of STEEL (as opposed to Aluminum)?

I have also 'heard' they test the "permanent muzzle devices" with a torque wrench up to 200 Ft/lbs. But I could not find any reference to that testing guideline on the ATF site. Do you know where they're hiding that?

Thanks in advance.

RJ

[JustinJ]

Thanks, Texasrifleman.

[TexasRifleman]

I have looked but couldn't find this particular piece of information: Is there anywhere in the ATF guidelines that says a muzzle device needs to be made of STEEL (as opposed to Aluminum)?

I have also 'heard' they test the "permanent muzzle devices" with a torque wrench up to 200 Ft/lbs. But I could not find any reference to that testing guideline on the ATF site. Do you know where they're hiding that?

Never heard either one of those things before, sorry.

[Sam1911]

Is there anywhere in the ATF guidelines that says a muzzle device needs to be made of STEEL (as opposed to Aluminum)?
I'd imagine not, however, there are some special things to consider when figuring out that "permanent" attachment if you're using such dissimilar metals. High temp soldering can work (I think) if flux and solder are appropriate, but 1,100 is only about 100 deg. away from melting the Aluminum part.

Welding the barrel and muzzle device together (obviously) won't work.

Pinning and then welding over the hole could work, but wouldn't be the job for most amateurs.

[Strykervet]

Okay, I've had this done, I installed a Brakeout on an M4 barrel, and I'll tell you what I learned.

Apparently, if you get questioned, say at a range, it is trial by fire. In case you don't know what that means, it comes from the witch hunt days where if you were drowned and died, you were guilty, God didn't save you. If you came up alive, you must be posessed so back down you went. Same with fire, survive and God saved you, die and you died along with the demon that posessed you.

ATF trial by fire works like this. They take your barrel and put it in a barrel vice and they hit with a breaker bar. Same kind they use to take off lug nuts. A torque wrench may be used, but at 200ftlbs, most average humans are putting their all into it without extra leverage. So imagine the ATF agent with your rifle trying his damndest to get it off with a breaker bar. They do in fact ruin your barrel, as no muzzle device can have that much torque applied without ruining the dimensions of the most critical part of the barrel.

But what is ruined? To you or me "ruined" means once the barrel is damaged it is junk. Won't shoot straight. To ATF, if they can remove the device and it still functions (forget about groups) then it is now an illegal SBR.

So, do you trust silver solder now? Do a search in Google images of silver soldered brakes removed. Try searching for it a few different ways. You'll see it doesn't work.

Blind pin is the way to go. Double blind pin is even better, and in fact, there are a couple of different ways to do it. But this HAS to be done by someone that knows what they are doing, both to get it right so the ATF gorilla can't get it off without ruining it, and so that you don't ruin the barrel because he drilled to close to the bore (or God forbid into it!).

I can give you the name of a place that will do it cheaper than ADCO and they do a great job. Rainier Arms in WA (which is local for me) they have a Boeing welder do their blind pin jobs as a side job (they are popular here, no SBR's). That guy did mine so slick that you almost can't tell it was pinned at all. The weld is a perfect dot over a hardened rod drilled into the barrel. He did it in such a way as to not damage the threads at all, nor the expensive AAC mount, he was able to get the pin in the actual barrel behind the threading.

Now if you try to remove this device, what happens in that hardened rod has nowhere to go and it can't break easily because of how it is welded in place. So the force applied to it tends to cause the hardened pin to twist the barrel shut. It basically pinches them shut, they cannot be fired. Ruins them.

Search for images of that too. You'll see if you compare silver solder to blind pin jobs that have been wrestled loose, that the blind pin does FAR more damage to the weapon than does the silver solder, which it seems all it does is destroy the threading. You can't thread on another device, but you can fire that short barrel as is.

Now as to what the ATF does if they subject you to trial by fire and you pass... I never got that information. Do they give you a check? Buy you a new one? Blow off? How's it work once they violate our justice system and subject us to trial by fire? Since ATF stands for "Anything That Flies" I suppose whatever flies, whatever they can get away with.

The trial by fire is what I have issue with. If they would just say "blind pin" and be done with it that would be fine. But to say "yeah, do that" then come along and subject you to trial by fire is absurd.

So, bottom line, blind pin that baby and get it done by someone that knows what they are doing. I feel comfortable with Rainier Arms, but I've heard good about ADCO too. But with Rainier, it is only like $68 or so and a two or three day wait since I'm local, but shipping on just a barrel or upper shouldn't be too bad.

If you don't have the barrel or upper yet, they can do the whole shebang right there and send that out to you ready to go.

There are other ways I should mention before I go. One is welding it on. The heat can and will damage your accuracy, definitely don't do this with anything decent. Then there is that new radial welding technique that is very precise, but good luck finding someone with the gear willing to do it. I think AAC uses them to weld their suppressors.

[Strykervet]

I'd imagine not, however, there are some special things to consider when figuring out that "permanent" attachment if you're using such dissimilar metals. High temp soldering can work (I think) if flux and solder are appropriate, but 1,100 is only about 100 deg. away from melting the Aluminum part.

Welding the barrel and muzzle device together (obviously) won't work.

Pinning and then welding over the hole could work, but wouldn't be the job for most amateurs.
Pinning and welding is the way they recommend it to be done. Silver solder works, and would be fine if there weren't an ATF willing to try you by fire!

Go look at what happens to a muzzle when the a blind pinned brake or hider is wrenched off. Go look at a silver soldered one. Then tell me which one you feel more comfortable owning while standing next to the ATF guy with the breaker bar.

I'd refrain from using an aluminum muzzle device. Simple reason being that if you blind pin it, and they try to force it off, chances are the brake will spin while the pin cuts a groove in it and does little or nothing to the barrel. I'd use steel on steel, no doubt about it.

[Sam1911]

Srikervet raises an interesting point with regards to muzzle devices. An aluminum copy of 'most any common flash hiders will never stand up to 200 ft. lbs. (and really, whatever leverage over that someone could produce with a bar) without simply snapping into bits from the torsion.

Well, now you have a barrel that's too short. But only because they broke part of it off. If you mount didn't fail, they simply destroyed part of it through the testing process, how would that stack up?

[Sam1911]

I'm thinking of something like the three-prong flash hider design. If the three prongs shear off, well, now your barrel is under 16"!

[TexasRifleman]

This is one of these ATF horror stories that crops up all the time. Everything Strykervet says is possible, but that doesn't mean it has EVER happened or that it would happen. I'd be interested in seeing something that shows this has ever actually happened to anyone.

The extremes are always possible but if we are going to worry about them then we probably shouldn't own any semi auto rifles at all, there's always a chance someone somewhere with enough time and energy could get one to double and make a "machine gun" out of it.

[Ghost Tracker]

If the costs of a suitable (steel?) flash hider and the $$ to have the process professionally double-pinned & blind welded get very high, why not just go ahead and SBR the thing? Or buy another 16" barrel?

[JustinJ]

I've seen a factory DPMS AR with 11" barrel and 5" dissipator style flash hider that appeared to be soldered on so would assume they verified in advance it was within ATF regs before selling.

On the other hand I've been planning to SBR an AR but didn't want to do this one as it is a Colt LE receiver so doing so would destroy any collector value. I shoot it regulary anyways so what the hell, SBR it is.

[Ranger30-06]

Just a question here, but what if you used Marine Tex on the threads then put the break on and let it dry? I mean that stuff essentially welds the two together unbelievably strong. Do you think that would qualify as legal?

You wouldn't be able to ever get it off, but it would only take about 2 minutes to do and even the biggest newbie could do it with his eyes closed being that it goes on as a liquid paste and drys as hardened steel.

[Ghost Tracker]

what if you used Marine Tex on the threads At 1100 degrees F, Marine Tex would be Silly Putty.

[Sam1911]

Well, unfortunately the ATF didn't say, "Anything that gives you 200 ft.lbs. resistance to unthreading...."

"Full-fusion gas or electric steel-seam welding, high-temperature (1100°F) silver soldering, or blind pinning with the pin head welded over," seems to be an inclusive list. You'd have to ask if other methods are acceptable.

Marine Tex starts to give up at sustained temps of 250 deg F. Even 50/50 (soft) solder would hold up to more than that (more like 370 deg. F). And neither get close to the ATF's stated standard for hard solder (1,100 F).

[rjrivero]

This is more than just a mental exercise to me. I actually had this built at ADCO:

http://www.revolverforums.com/forum/picture.php?albumid=46&pictureid=284

It's a cut down barrel with a large muzzle device to bring it to 16.25" With the suppressor attached the OAL is 17".

The muzzle device is aluminum. It is set with RED locktite, and it is pinned and welded to the barrel. It's just a 9mm and no full auto, so I doubt I can get it hot enough to burn through the Red Locktite anyway.

It is pinned with set screws to the barrel, and then there are aluminum pins over the set screws. The aluminum pins are welded to the aluminum tube, and then smoothed.

So, This is blind pinned and welded over the pin holes, per ATF instruction.

I think my best bet is to send it to the ATF for testing and classification. Then I would have a letter in my hand, which may or may not save me any hassle down the road.

The reason I built this upper is because of that silly Michigan Law allowing suppressors and forbiding short barrel rifles.

Edit: As it so happens, I have an email address from one of the Technology Division guys at the ATF. I fired off an email and will wait to hear from him. I'll give him a follow up phone call tomorrow and discuss this with him.
I'll keep you posted.