Using polychoke to meet minimum lengths

19-3Ben · May 4, 2014

I hope this question is in the right spot. It's actually about how to AVOID an NFA issue by keeping a shotgun barrel above the 18" min. I figure who better to know about this, than you guys!

I'm thinking of getting a shotgun to play with. I want it to be very light, and break down so that it can fit in a small camping bag. I'm thinking a break action single barrel 12ga would be nice (H&R topper or the like). Now, here's the trick. I wondering if I could cut down the barrel to below 18" (would probably go to 16.5" or so) but braze on a polychoke to get it back up to around 18.5" total length. I would make sure I had at least a 1/2" of wiggle room above the 18" min barrel length so that if my measurement is a little off I am sure not to have bought myself time in the Greybar Motel.

I figure it would kind of like a fixed muzzle brake at the end of a 14.5" AR15 bbl to keep it above min length.

I figure the polychoke might make it a more versatile gun, and keep things legal while near the minimum length. I have always seen polychokes as a gimmicky thing from days past, but I think it actually might have a real useful application here.

Any thoughts?

Badger Arms · May 4, 2014

The trick is that it has to be welded or brazed on, not silver-solder or epoxy. The portion that is fixed is the only portion that can count towards the 18" minimum. Also, PLEASE ensure that you are measuring to the breech face, not to the end of the barrel. I've caught a few people who were just taking the barrel and measuring the length of the barrel, including the locking extension. Another caution is that you cannot assemble the gun after you cut it. You also can't cut the barrel and then leave it for a few months while you go and do honey-do's. Were it me, I would take the gun apart and leave the receiver with the neighbor. By NFA 'rulings', if you have control of the parts even if they are not assembled, you have an unregistered SBS. I don't want Uncle cat-stomper to bash in the door and shoot me because I am in the process of cutting and brazing.

19-3Ben · May 4, 2014

Badger- great advice! I didn't realize only the fixed portion counts toward the length. I'll have to see just how much of it is fixed. I think there is an internal portion of the polychoke that goes pretty much up to the end, but I would need to double check it. Will definitely give the receiver to someone else while working on this.
Might even pay, depending on cost, to just give it to the gunsmith to cut and braze for me. For the peace of mind, it might be worth it, again depending on cost.

Badger Arms · May 4, 2014

Another option is to have the barrel cut to 18.5" and then have it threaded for choke tubes. If your primary goal is to have a barrel you can put choke tubes in. There is a guy that will do it for $75 for just the threading, $135 with three choke tubes: http://www.ar15.com/forums/t_7_143/547242_Screw_in_choke_tubes_installed.html

19-3Ben · May 4, 2014

Badger- that's a great idea and definitely something to consider. On the one hand, I like that with a polychoke, I'd have "on the fly" capability to change the choke without having to carry extra chokes in the bag and without having to screw/unscrew to change out.

On the other hand, the polychoke is a bit clumsy! It's like the dork-disk that comes behind the gear set of a new bike!

pjeski · May 5, 2014

Silver solder (1100F) is fine for permanent attachment.

Jim K · May 5, 2014

For actual strength, yes, but IIRC, BATFE requires muzzle attachments to be welded on if they are used to meet minimum length requirements.

Jim

pjeski · May 5, 2014

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

Badger Arms · May 6, 2014

"Brazing" is the proper term for 1,100 degree or higher joining of metals as you describe. That the BATFE describes it as silver soldering, but there are "silver solder" products that melt at much lower temps.

Arizona_Mike · May 7, 2014

Jim K said:
For actual strength, yes, but IIRC, BATFE requires muzzle attachments to be welded on if they are used to meet minimum length requirements.

Jim

The ATF spells out exactly what is acceptable.

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

Mike

Arizona_Mike · May 7, 2014

Badger Arms said:
You also can't cut the barrel and then leave it for a few months while you go and do honey-do's. Were it me, I would take the gun apart and leave the receiver with the neighbor. By NFA 'rulings', if you have control of the parts even if they are not assembled, you have an unregistered SBS. I don't want Uncle cat-stomper to bash in the door and shoot me because I am in the process of cutting and brazing.

After fighting it for years, the ATF finally embraced the language of US v. Thompson-Center in 2011 (Ruling 2011-4):

A firearm, as defined by the National Firearms Act (NFA), 26 U.S.C. 5845(a)(3), is made when unassembled parts are placed in close proximity(emphasis mine) in such a way that they . . . serve no useful purpose other than to make . . .

I used a safe deposit box instead of a neighbor, but I think physical separation is protective.
Mike

Using polychoke to meet minimum lengths

19-3Ben

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