[lordofwar2]

if you put a muzzel arrachment on a ak to bring it up to 16 inches,do you think if you weld the pin that holds it on so it cannot be removed that it would be considered permenment?you cannot remove it because the pin is welded to the attachment.just wondering if this would be good enough.

 

[dead_eye]

That is actually how it is done. The device is blind pinned (can not drive it out the other side) and the exposed end of the pin is welded over, file flush, touch up to match. :grin:

 

[Surly]

The pin has to be 1/8" and be drilled through the brake and into the barrel to qualify. The detent pin that times the brake doesn't count.

 

[MASP7]

The pin has to be 1/8" and be drilled through the brake and into the barrel to qualify. The detent pin that times the brake doesn't count.

Where does it say that the pin has to be 1/8"?

Not my personal opinion... This is what the BATFE says in the National Firearms Handbook, Page 6
http://www.atf.gov/publications/downloa ... 5320-8.pdf

2.1.3 Rifle. A rifle is a firearm designed to be fired from the shoulder and designed to use the energy ofan explosive in a fixed cartridge to fire only a single projectile through a rifled barrel for each single pull of the trigger. A rifle subject to the NFA has a barrel or barrels of less than 16 inches in length.

The ATF procedure for measuring barrel length is to measure from the closed bolt (or breech-face) to the furthermost end of the barrel or permanently attached muzzle device. 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. Barrels are measured by inserting a dowel rod into the barrel until the rod stops against the bolt or breech-face. The rod is then marked at the furthermost end of the barrel or permanently attached muzzle device, withdrawn from the barrel, and measured.

 

[loner42]

I wonder what their solution or requirement would be in the case of the m92's when you want to perm. attach an Aluminum fake can as a barrel ext.? You would'nt be able to weld or silver solder, and if the can was anodized you would'nt want to try and weld on top of a blind pin.
I don't see the need for weld on top of a blind pin anyway, you can't remove the pin without drilling it out and you could also drill one out that was welded over. So what's the point ? Just another stupid law that makes no sense.

 

[lordofwar2]

i got a fake pbs5 can from copes for the krink build.it has no spot for the detent pin.i figure screw it in until it bottoms out i turn it a little until it looks right and dremel a spot for the detent,then weld the pin to the can and file smooth and touch up.thanks for the info.i figure in case i ever want to sbr it i would just dremel out the weld and the pin,unscrew it get a new detent pin and be good to go.better than wrecking the threads on the barrel attachment.once the pin is welded to the fake can you cannot remove it without tools.

 

[loner42]

Well first of all the can has to be pinned to the barrel not the FSB by way of the detent pin. Secondly how would you weld a steel pin to an aluminum can? I believe you need to rethink your plan.

 

[Surly]

Where does it say that the pin has to be 1/8"?

Not my personal opinion... This is what the BATFE says in the National Firearms Handbook, Page 6
http://www.atf.gov/publications/downloa ... 5320-8.pdf

I can't recall where I saw a letter and I don't have the time or desire to scour the intardwebs looking for it. Use whatever you want, I really don't care. :twisted:

 

[MASP7]

I can't recall where I saw a letter and I don't have the time or desire to scour the intardwebs looking for it. Use whatever you want, I really don't care. :twisted:

Well I noticed that you have time to post unsubstantiated "facts" and the be a d**k about it when someone questions their veracity.

Thanks for all of your help. :twisted:

 

[Storydude1]

Well first of all the can has to be pinned to the barrel not the FSB by way of the detent pin. Secondly how would you weld a steel pin to an aluminum can? I believe you need to rethink your plan.

Why would he have to weld the pin to the can?

Set blind pin below surface of can, Tig weld and use Al. filler rod. Per ATF specs "Blind Pin" means one that is not removable without intent.

Nowhere does it say the pin must be welded to anything, just the pin-head must be welded over. Or Silver soldered. Or Totally welded.

 

[MASP7]

Based On what I know, I think that it would satisfy the BATFE requirement if you used a steel pin, left it below the surface and TID'ed it over with aluminum filler. It would be possible to use an aluminum pin, but I would question the sheer strength of it. Perhaps there is a very hard, strong aluminum pin out there that is weldable.

Also, remember that the can needs to be a permanent and integral part of the barrel, not the front sight base that the can attaches to. The FSB is just pinned to the barrel and is not permanent. The pin needs to go through the front sight base and into barrel, and then welded over.

 

[lordofwar2]

as we all know on a regular ak the barrel is threaded.on a krink the fsb is threaded.if you have to pin to the barrel that means drilling through the fsb threads and into the barrel with a pin.i am know law expert and i know common sence does not apply to government,so i will have to do more reserch.can anybody who has pinned a fake can on a ak74 krink chime in on how they did it.thanks for all the input.

 

[AKBLUE]

Easy enough to blind pin the 24mm FSB through the underside in the cleaning rod channel using a threaded allen screw and weld it in place. Then pin the 24mm brake by a small pin to the FSB 24mm threaded area..., as noted aluminum weld likely needed or aluminum pin.

 

[lordofwar2]

that sounds doable.or maybe because i screwed up my fsp front hole,i can put the new front site pin in,and weld up the hole i made when i drilled crooked.this will weld the fsb to the barrel and then pin fake can to the barrel.thanks for the info.

 

[AKBLUE]

I don't know that welding a FSB pin in the existing channel qualiies as a "blind pin" for BATFE regs. A blind pin has only one way into a blind (no exit) hole.

 

[MASP7]

I don't know that welding a FSB pin in the existing channel qualiies as a "blind pin" for BATFE regs. A blind pin has only one way into a blind (no exit) hole.

I would agree. Blind means just that- "having but one opening or outlet".
The FSB pins do not qualify unless you would want to weld up one side of the FSB pin hole, insert the pin and the weld the pin head. Then you (possibly) have the uphill battle of arguing what you did is in compliance with the generally accepted practice.

Seems like the long way around the barn.... especially when you can drill a hole on the bottom of the can into the FSB and into the barrel. Pin it securely and fuse metal over top of the pin.

 

[HobbyMachinist]

I think you guys are over thinking this issue.
If an ATF agent were to ever examine your rifle, he not gonna break out the grinder to see what size pin you have and what kind of weld job you did.
He's gonna ask you who did the work. When you relpy that you did it, and that it is blind pinned on, He's gonna look for holes and he's gonna see if it unscrews. No holes, and on tight, and you're on your way.

That's my take on the issue anyhow.

 

[AKBLUE]

Hobby Machinist., while I agree with the solution as a personal choice.., I think there is a line between what "I" would do and what advice to another who may not be doing it themselves or what advice is deemed technically "legal". Intent being the operant word in most cases. Yes..., over thinking and not sure many violations of this sort are ever enforced but nobody wants to be the first in line either. :dance:

 

[65cobra]

I don't get how welding or pinning anything to the FSB does anything, ok that would work but you would still need to blind pin/weld the FSB to the barrel as well. So you are welding two things so whats the benefit?

Is silver solder the same stuff that I use to solder electrical wires and plumbing or is it diffrent? Also when using an aluminum extension what about putting the steel blind pin and covering it with silver solder. Does it bond to aluminum enough to stay in there it should be easy enough to finish over. I think this is more of a materials question than an atf question.

 

[MASP7]

I don't get how welding or pinning anything to the FSB does anything, ok that would work but you would still need to blind pin/weld the FSB to the barrel as well. So you are welding two things so whats the benefit?

I think that point has been made a couple of times.

Is silver solder the same stuff that I use to solder electrical wires and plumbing or is it diffrent?

No. That is lead/tin solder that melts as low as 370 degrees F.
The silver solder that is BATFE approved for permanently attaching muzzle devices can't melt below 1100 degrees F.

Also when using an aluminum extension what about putting the steel blind pin and covering it with silver solder.

BTAFE says the metal on the blind pin needs to be "fused", not soldered.

I think this is more of a materials question than an atf question.

Well, you can think that all you want, but the BATFE decides what is acceptable and what isn't. If you don't do it correctly you are in jeopardy of losing your freedom, or at the very least, losing the weapon and paying a lot of expensive legal bills.

The silly thing is that the BATFE tells you more than a couple of acceptable ways to do it, yet people always want to push the limits.