22_Shooter 1,560 Posted September 16, 2007 Report Share Posted September 16, 2007 (edited) In NY state, muzzle brakes are only allowed if they are permanently attached. I only knew of soldering it to get this done, but just read about "blind-pinning" to get the same effect. Saw it on ARFcom, but don't (can't) have an account there, so I'm asking here...............What exactly is blind-pinning? Edited September 16, 2007 by 22_Shooter Quote Link to post Share on other sites
nalioth 405 Posted September 16, 2007 Report Share Posted September 16, 2007 (edited) Screwing or pressing on your muzzle device (the really evil one, ya know). Drilling a 90 degree hole through the muzzle device into the barrel a short ways. Welding over the pin and grinding to normal muzzle device contour. Thanks NY and CA. Note 1: It's considered 'bad' to drill all the way through your barrel when doing this. Note 2: Century disregarded Note 1 on several Cetme rifles. Edited September 16, 2007 by nalioth Quote Link to post Share on other sites
22_Shooter 1,560 Posted September 16, 2007 Author Report Share Posted September 16, 2007 OK, thanks for the info. So is it "safer" to get my barrel threaded and a brake soldered on? Or is blind-pinning a fairly easy task for a gunsmith? I don't wanna have my barrel mucked up if they drill too far. Quote Link to post Share on other sites
Etek 32 Posted September 16, 2007 Report Share Posted September 16, 2007 Soldering is out of the question. You either have to Silver solder it, use four equally spaced welds, or weld at least halfway around the barrel in order for it to be permanent. This according to the BATFE Quote Link to post Share on other sites
nalioth 405 Posted September 16, 2007 Report Share Posted September 16, 2007 (edited) As Etek points out: The 4 approved methods are 1) blind pinning 2) high temperature silver solder (1200 degrees or better, i believe) 3) tack welds at 12, 3, 6 and 9 o'clock 4) continuous weld of at least 50% of the contact area If you get a good smith, he won't screw up the blind pinning. If you're gonna blind pin, you don't need to thread the muzzle, just find a press on muzzle device. Edited September 16, 2007 by nalioth Quote Link to post Share on other sites
22_Shooter 1,560 Posted September 17, 2007 Author Report Share Posted September 17, 2007 OK, thanks to both of you. You cleared a lot up for me. Quote Link to post Share on other sites
ArcFault 4 Posted September 17, 2007 Report Share Posted September 17, 2007 I thought that blind pinning was just a pin press fit into a blind hole, the idea being that you don't have to solder or weld. Quote Link to post Share on other sites
nalioth 405 Posted September 17, 2007 Report Share Posted September 17, 2007 I thought that blind pinning was just a pin press fit into a blind hole, the idea being that you don't have to solder or weld. Not according to the alphabet gang in regard to firearms. Quote Link to post Share on other sites
ArcFault 4 Posted September 18, 2007 Report Share Posted September 18, 2007 I guess that means that theres no reason to blind pin then. It's less work to tack weld or silver solder. Odd. Quote Link to post Share on other sites
cscharlie 107 Posted September 18, 2007 Report Share Posted September 18, 2007 (edited) The more heat that you apply to your barrel, the more accuracy you will tend to loose. When you blind pin, you can tig weld a little spot over the end of your pin inwich is a little recessed from the surface of the flash hider. It's too prevent it from being removable. If you solder the flash hider, you need to use silver solder, that requires heating well over 1000 degrees according to the BATFE in order for it to be considered perm attached if I remember correctly. The small weld over the end of a pinn would be applying less heat to the barrel steel. That is a good reason to blind pin. Edted to add: After it's pinned, if you realy wanted to, you could grind around the pinn and through the weld and pull the pin out to change the flash hider. If you weld it directly, you might have to cut your barrel to remove it. Edited September 18, 2007 by cscharlie Quote Link to post Share on other sites
hcpookie 0 Posted October 25, 2007 Report Share Posted October 25, 2007 The information I've collected on Blind Pinning is here, originally found on the FALFILES: http://pookieweb.dyndns.org:61129/AK/docs/...l/blind_pin.htm HTH Quote Link to post Share on other sites
acercanto 6 Posted October 25, 2007 Report Share Posted October 25, 2007 I wonder how hard/safe it would be to put your blind pin through the barrel at an angle so that it came out on the other side without entering the barrel, FSB style, like that. You could then weld both ends, file down, and refinish and nobody'd be the wiser... Hm. Acer Quote Link to post Share on other sites
nalioth 405 Posted October 25, 2007 Report Share Posted October 25, 2007 I wonder how hard/safe it would be to put your blind pin through the barrel at an angle so that it came out on the other side without entering the barrel, FSB style, like that. You could then weld both ends, file down, and refinish and nobody'd be the wiser... Hm. Acer I believe the alphabet boys specify a 90 degree blind pin. The actual regs do contain quite detailed specs. Quote Link to post Share on other sites
RDSWriter 5 Posted October 26, 2007 Report Share Posted October 26, 2007 I wonder how hard/safe it would be to put your blind pin through the barrel at an angle so that it came out on the other side without entering the barrel, FSB style, like that. You could then weld both ends, file down, and refinish and nobody'd be the wiser... Hm. Acer I believe the alphabet boys specify a 90 degree blind pin. The actual regs do contain quite detailed specs. I'd actually like to know the answer to this one... pinning all the way through and welding. My supposition is that the method is probably okay or likely to be approved by the ATF as it would be as difficult to remove a pin welded in two places as it would a pin that could be drilled to remove the weld and then drilled and tapped to remove from the hole. Just write the Tech Branch and ask. Funning thing though... is that (1) it would be harder to pin all the way through than to pin the 'approved' blind way, (2) it would require cleaning up two welds, and (3) it would apply more heat to accomplish. Quote Link to post Share on other sites
Twinsen 86 Posted October 27, 2007 Report Share Posted October 27, 2007 Screwing or pressing on your muzzle device (the really evil one, ya know). Drilling a 90 degree hole through the muzzle device into the barrel a short ways. Welding over the pin and grinding to normal muzzle device contour. Thanks NY and CA. Note 1: It's considered 'bad' to drill all the way through your barrel when doing this. Note 2: Century disregarded Note 1 on several Cetme rifles. You forgot the even worse state of CT. We can't own any AK varient in 7.62 and need to do everything else you guys do. We have no magazine restrictions though. I can't wait to get a 74 style MB on every AK I own. Quote Link to post Share on other sites
loner42 6 Posted October 28, 2007 Report Share Posted October 28, 2007 A properly installed blind pin should not have to be welded over as it would be next to impossible to remove without drilling it out. I'm talking about a .0005- .001 press fit. The letter from BATF to Wilson was regarding using a 6-32 set screw not a press fit pin. If i were doing it, i'd install the pin leaving it a little proud and file it flush and call it good. I'd like to see someone remove it without drilling it out.................. My 02 centavos Quote Link to post Share on other sites
hcpookie 0 Posted October 29, 2007 Report Share Posted October 29, 2007 HRM you guys don't follow links do you? OK here you go: Original Link Here:http://www.falfiles.com/forums/showthread....ht=blind+muzzle "...printed from the Wilson Combat website back in April 2000. The source is the ATF, in response to a letter about the attachment method from Wilson Combat. The author is Edward M. Owens (hence the EMO at the top) the now-retired head of ATF Firearms Tech Branch." /Begin quote: DEPARTMENT OF THE TREASURY BUREAU OF ALCOHOL, TOBACCO AND FIREARMS WASHINGTON, DC 20226 FEB 2 2000 903050:EMO 3311 Mr. XXXX XXXXXX XXXXXX XXXXXX XXXX XX XXX XXXXXXXXXX, XXXXXXXX XXXXX Dear Mr. XXXXXX This is in reply to your letter dated December 28, 1999, in which you ask about permanently affixing muzzle brakes your firm produces to barrel muzzles of "post ban" AR15 type rifles. You indicated that the barrel muzzle will be threaded to accept the muzzle brake. The brake will be screwed to the barrel muzzle and a 3/32 inch hole .030 - .050 inches in dpeth will be drilled into the barrel wall using an existing set screw location in the brake as a pilot hole. A 6X32 TPI set screw will be installed through the pilot hole and into the described blind hole in the barrel. The set screw hole will be welded over after installation of the screw to permanently affix the brake to the barrel. Excess wild will be removed and the muzzle brake refinished to conceal the location of the weld. The above described procedure has previously been approved for use in permanently affixing muzzle attachments to rifle barrels. An AR15 type rifle barrel having a muzzle brake affixed as described above would no longer be considered to have a threaded muzzle provided that deep penetrating steel fusion welding is used. /End quote Quote Link to post Share on other sites
dk8019 5 Posted January 3, 2008 Report Share Posted January 3, 2008 This is bringing up an older topic, but I've seen muzzle brakes attached this way to maintain barrel length. It's impossible to remove without drilling, yet it seems there's a lot of insistence on welding over it. Any other input here? A properly installed blind pin should not have to be welded over as it would be next to impossible to remove without drilling it out. I'm talking about a .0005- .001 press fit. The letter from BATF to Wilson was regarding using a 6-32 set screw not a press fit pin. If i were doing it, i'd install the pin leaving it a little proud and file it flush and call it good. I'd like to see someone remove it without drilling it out.................. My 02 centavos Quote Link to post Share on other sites
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