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Need advice on a project

John A.

John A.

Unconstitutional laws are not laws.
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According to the Supreme court in Thompson Center vs ATF, common knowledge, and even ATF memo letters, it is legal to turn a handgun into a rifle.

Provided that a 16 inch (or greater) barrel is used, and the overall length is 26.0" or more.

OK, my question starts getting into the proper way to pin and weld a barrel to be in compliance with ATF reg's.

The barrel extension would be made of aluminum, but would be screwed onto the barrel, a hole drilled through the aluminum and down into the outer portion of the barrel and a steel locking pin inserted and then tig welded over top of the pin to prevent it from being removed without requiring tools to revert it back to a pistol.

OK, for a better explanation, I am thinking of pinning one of my silencers onto my scorpion permanently so I can add a stock without the need to double stamp the gun as an SBR. I could leave the front cap threaded so I can still clean the baffles every now and then as needed.

I stuck a rod down through the silencer and barrel until it bottomed out onto the closed bolt face. This is the method the ATF uses to measure barrel length.

If it were permanently attached, came out to a little more than 16 inches without the front cap.

I'm mainly just wanted to check with the welders here to make sure I can tig weld over steel inside of aluminum. I'm not trying to weld the steel to the aluminum. I already know that won't work. I am asking if I can weld over the steel to basically block it in there and keep it from falling out. Essentially blind pin it.

Now on to minimum overall length.

With an AR15 stock installed and extended would be about 36 inches, which is way more than the 26 inch minimum I would need it to be.

The factory carbine versions of the scorpion comes with a 16 inch barrel, and a folding stock from the factory, so ATF may not be measuring the overall length with the stock folded. I have asked on cz forum if someone could measure the OAL with the stock folded to give me a little better piece of mind because if atf is requiring 26 inches when it's folded (in its' shortest position), mine wouldn't be long enough and I would have to add a fixed stock instead of a folder.

But since a rifle, by both atf and legal definition is intended to be used as shoulder fired, I am inclined to believe they should measure to the end of the stock while it is extended. Which is part of the overall length in my humble opinion, but I would appreciate if anyone has a definitive answer of how to measure OAL with a folding stock if they would share it.

Oh, just for the record, here is a factory carbine. Mine wouldn't be identical, but it's worth noting that they are imported with folding stocks.

pix985100581.jpg
 
Found out that the factory carbines measure 24 1/2" overall with the stock folded, so ATF is certainly measuring them with the stock open/extended.

I thought that was how it should be measured, but it's good to know without a doubt in case I do make up my mind to convert it to a rifle.

I also think it would be OK to tig weld over the steel pin, but I know there are some welders here that have a lot more experience than I do.

I'm not welding the steel to the aluminum. Simply inserting the steel in the hole, and welding over top of it to prevent it from falling out and to lock the can in place with the barrel so it can't be unscrewed.

If I do decide to dedicate the silencer to that specific gun in the end.

I want to, and I also question whether I want to lose moving that can around to other guns is my dilemma. So, I'm going to think about it a while to make sure it's what I want to do.
 
Very neat looking project. I would have only one possible mark in the con column. Cleaning the weapon itself and pushing crap into the can. Im gonna wager youve thought of this already and may have solution.
 
Yeah, I have.

The front cap would still be able to be unscrewed off of the tube, and the baffles can be removed for cleaning.

Whether cleaning the gun itself, or cleaning the baffles to remove any buildup over time, though 9mm isn't terribly bad for that. It usually just has more fouling than anything, and I don't concern myself with that much.

The tube and the rear endcap would be permanently affixed to the barrel though to bring it to the minimum 16 inch barrel requirement.
 
Thanks for the link scoop.

Especially that specific link.

I have a shockwave blade on it now.

And is another reason why I'm somewhat hesitant.

I like the shockwave.

But no doubt, I would like to be able to be shoulder the gun. (real stock)

And a vertical front grip.

But, I just don't know if I want to dedicate the can to that gun or not. I swap that can out to a lot of other guns. And it's not near as heavy as my first 9mm can.
 
My advice as far as the extension, would be to put an aluminum plug, of the same alloy into the pin bore, once it's pinned. That would make putting a spot weld in much easier, then it can be machined down.

My only question is, does the pin/weld have to be visible to prove compliance?
 
To my knowledge, it doesn't have to be visible, though I probably would a little just so I would know where to drill it back out at if I ever wanted to and so I could point it out to anyone who would be questioning whether it was perm attached or not.

And it would be at the 6 o'clock position too just because that's the least noticeable place to do it.

To my knowledge, if anyone were to check to see if it was permanently attached, they'd probably just try to unscrew it.

Once it got to the point where anyone would be trying to remove it with tools, should show that it's not just going to come apart like a normal silencer and I'd be getting pretty hateful with them in case they bent the .058" aluminum tube they'd be buying it if they did. I never tighten mine so tight I need strap wrenches to get them to come loose.
 
What if ATF measures from the adapter with can removed, or disassembled (such as for cleaning)? Technically, the gun will still fire, correct?

As for welding aluminum over a steel pin, it can be done but there will no doubt be a void and/or air/impurity pocket of some sort under the weld. I always wondered how ATF would/could know if there is actually a pin under a welded flash hider on a 14" barrel. (for example)
 
The can (rear end cap and the tube) wouldn't be removable. It would be affixed to the barrel to add to the length so it would reach the magical 16 inches by the pinning/welding.

Same method as how folks pin and weld a long flashider onto a barrel that is less than 16 inches long to bring it to legal length, but in my case would be a long tube instead of a muzzlebrake or flashider or whatever.

I have taken some measurements, and the length would still be 16 inches even if the front endcap was removed so it would still be 16 inches with the front cap off so I would definitely be in compliance without having to SBR the gun.

And would allow me to remove the front cap to clean the baffles and the gun without being too short like you mentioned. Thanks for looking out though because that was one of my concerns too. I checked that last night and it turns out to be about an 1/8th of an inch longer than it has to be, so I'm good on the length.

I'm just trying to decide whether I want to gain the ability to add a stock and a front grip or lose the ability to be able to use the silencer on any of my other guns.

It's one of those "Is the glass half empty or half full" kind of decisions.
 
I see, the suppressor disassembles from the front...

Getting back to pinning--how will ATF "know" there is actually a pin under the weld? I don't imagine they go putting a wrench on it. The length law is SO outdated... :rolleyes:
 
You're probably right Bobster, I may never be checked, but if I'm going to do something, I'm going to do it right.

I have found that I sleep better at night, and life is so much easier that way.
 
I looked at a number of images of pinned flash hiders to satisfy my curiosity. Not really much to it--drill a hole through the flash hider into the barrel, tap in pin, weld over. At the very least the flash hider will be destroyed if it ever needed to be removed for any reason and most likely severe damage will be done to the barrel. I note that many "kits" include a crush washer that might lose its temper once heated when maybe shims or spacers would be a better idea.

Perhaps you could use an aluminum pin which would certainly not be as durable as steel but could more easily be welded to the suppressor housing and removed (by milling/grinding), if necessary.

I'd be a little apprehensive devoting a suppressor to just one gun considering the (current) difficulty and expense of getting one. But that's just my $0.02...
 
I am apprehensive about devoting a can to a single gun.

Though, I have 3, and waiting on the approval to build the fourth.

It's been a few days now, and I'm still on the fence.

I may just leave it as a pistol for the time being.
 
Bobster said:
. . . Perhaps you could use an aluminum pin which would certainly not be as durable as steel but could more easily be welded to the suppressor
Click to expand...


How are you going to weld an aluminum pin to a steel suppressor?
 
My endcap is aluminum. So, that's why I mentioned a tig welder.

The pin would be steel, and I wouldn't be welding it "to" the endcap.

The typical method of blind pinning is to install the barrel extension (this case my can)

I would drill a hole the diameter of the pin through the endcap and somewhat below the surface of the barrel at the barrel threads, and then tig weld over top of the pin to seal it in place to prevent it from being unscrewed off of the barrel.

I have decided that I enjoy using the suppressor on other firearms too much and am not going to go this route. I'm just going to shoot it as I have been.
 
I know it's been a while since the topic died, but I am still thinking about this project.

Now am considering making a barrel extension.

It will be similar to one of the Car15 barrel extensions that get put on the 11.5" AR barrels to bring them to legal length, with the exception of having a male threaded end so I can install/remove my can. And longer.

That is if I can bore the center straight enough because I don't want to risk damaging my baffles. I've never bored that deep on my lathe before and will almost certainly need to drill from both sides and meet in the middle.
 
flash-hider-5.5-inch (1).jpg I know you dig do your own but i bet Tony might would sell you the xm177 extension without the flash hider slots cut pretty cheap. He did a slide over xm177 hider(goes over a standard 16inch barrel with threads deep inside have a car15 or xm177 illusion) for me several years ago. Turned out quite nice. All you would have to do is cut your male threads. If i had to guess id bet maybe 25bucs ? Or less i just looked he does these for 20 bucs and you dont want the slots.
https://www.tonyscustomsllc.com/contact-us/
 
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Well, the scorpion has an 18x1mm RH barrel threads, as well as a lip that would need to be counterbored into the barrel extension.

And in order to get the minimum lengths for barrel and overall length to avoid the SBR tax, would need to be around 9 - 9-1/4" long.

I wouldn't necessarily mind having him make me one, but it would be different from what he would probably be expecting.
 
Ah my bad. I read car15 and had ar stuck in my brain not scorpion. Failure to read all on my part.
 
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