I think I'd rather just use a 16" barrel personally.
I showed Steve how to do it. It's super easy, I just don't have a welder in the shop.
I showed Steve how to do it. It's super easy, I just don't have a welder in the shop.
I had a long talk some time ago with a guy in the West Virginia ATF office (I think that is where it was). I wanted to do my 9mm barrel, but it is too thin at the threads. He suggested the solder, but also told me I could just weld it to the barrel, at the end. He said that the bottom line was; if it the weapon was ever to come in to their possession for what ever reason, the barrel would go in a vice, and a big pipe wrench would go on the muzzle device. If it came off, it wasn't permanently attached.
Anyway, I made a neat little 3/4" weld where my muzzle device meets the barrel. It is much stronger than a pin, but doesn't look as neato. It's covered by a floating rail/tube anyway. It will take more than a pipe wrench!
Anyway, he told me there are many a pin jobs out there that are done poorly, and preferred the 1,100 degree solder. As I understand it, it doesn't take 1,100 degrees to solder it. Just to get it back off.
If you have the pin, and the depth you want it sunk in your barrel, you can bring it by here. I have a mill and a TIG. Not that you'd need a mill.
Anyway, I made a neat little 3/4" weld where my muzzle device meets the barrel. It is much stronger than a pin, but doesn't look as neato. It's covered by a floating rail/tube anyway. It will take more than a pipe wrench!
Anyway, he told me there are many a pin jobs out there that are done poorly, and preferred the 1,100 degree solder. As I understand it, it doesn't take 1,100 degrees to solder it. Just to get it back off.
If you have the pin, and the depth you want it sunk in your barrel, you can bring it by here. I have a mill and a TIG. Not that you'd need a mill.
The best way I've found to do it is as follows:
You need to buy a 1/8" center cutting carbide end mill.
You need to buy a stick of 1/8" drill stock.
Grip the flats of the muzzle device in the milling vice or drill press vice.
Plunge the end mill through the muzzle device (center 3/16-1/4" from base of muzzle device leaving 1/8-3/16 from the edge of the pin to the edge of the muzzle device).
Screw the muzzle device on the barrel and put it back in the milling vice. with the flats to index the hole back where you had it.
Plunge end mill through hole in flash hider until it touches the threads of the barrel.
The threads are .030" deep, major diameter is ~.499" and groove diameter is ~.224. Not a lot of wall thickness left under the threads. .499/2 - .224/2 = .1375". You have 137 thousandths from the top of the threads to the bottom of the groves in the barrel so be careful. I would go around .050 - .060" deep from the top of the threads on the barrel.
Cut off a small piece of 1/8" drill stock and grind it so it sits just below the edge of the flash hider.
Tack weld over the pin head completely.
Grind/sand smooth
Degrease and cold blue the tack weld
I don't really like pinning/welding 1/2-28 threads on any barrel. There just isn't enough meat there and like Dave said, they're gonna put a big wrench on it. If you don't go all the way through the threads, it's a very weak pin job. If you go too deep, you've really thinned the wall in that spot. I think silver soldering is the best way to do it personally.
You need to buy a 1/8" center cutting carbide end mill.
You need to buy a stick of 1/8" drill stock.
Grip the flats of the muzzle device in the milling vice or drill press vice.
Plunge the end mill through the muzzle device (center 3/16-1/4" from base of muzzle device leaving 1/8-3/16 from the edge of the pin to the edge of the muzzle device).
Screw the muzzle device on the barrel and put it back in the milling vice. with the flats to index the hole back where you had it.
Plunge end mill through hole in flash hider until it touches the threads of the barrel.
The threads are .030" deep, major diameter is ~.499" and groove diameter is ~.224. Not a lot of wall thickness left under the threads. .499/2 - .224/2 = .1375". You have 137 thousandths from the top of the threads to the bottom of the groves in the barrel so be careful. I would go around .050 - .060" deep from the top of the threads on the barrel.
Cut off a small piece of 1/8" drill stock and grind it so it sits just below the edge of the flash hider.
Tack weld over the pin head completely.
Grind/sand smooth
Degrease and cold blue the tack weld
I don't really like pinning/welding 1/2-28 threads on any barrel. There just isn't enough meat there and like Dave said, they're gonna put a big wrench on it. If you don't go all the way through the threads, it's a very weak pin job. If you go too deep, you've really thinned the wall in that spot. I think silver soldering is the best way to do it personally.
If I was doing my 9mm again, I think I would have lobbed off the threaded end, and threaded the big barrel diameter to 5/8"-24, then pinned/weld or soldered. That way, when I clumsily hit something with the end of my long ass flash hider, I wouldn't risk damaging my paper thin end of my barrel. My 9mm AR has a .380" bore, and a .5" OD, not including the thread depth. That is thinner than .060". Makes me want to redo it right now, just thinking about it! Maybe I will just weld all the way around. I am clumsy.
I read a lengthy discussion somewhere about the 1,100 degree solder and being hot enough to anneal the barrel. I'm not an engineer or a metallurgist so in pretty ignorant on the subject. Dustin or Dave do you guys have any thought on that?
I don't believe 1100* is hot enough to affect the steel.
WD, I believe Dustin is correct.
I'm no metallurgist either, but I do know that TIG would not be as hot overall, as you are only focusing heat in a tiny area. Soldering requires the whole two chunks to heat up. I can lay a tiny weld with the TIG, and you grab the barrel a few inches away immediately after the weld. The heat will gradually spread as the weld cools, but you can control that. Wet rag, water, whatever. It is not a structural weld. It only has to hold a little pin in place.
I like the TIG thing (in theory, as I have done only mine) better for that reason, and because I am currently out of oxygen, acetylene, and have no 1,100 deg solder.
I'm no metallurgist either, but I do know that TIG would not be as hot overall, as you are only focusing heat in a tiny area. Soldering requires the whole two chunks to heat up. I can lay a tiny weld with the TIG, and you grab the barrel a few inches away immediately after the weld. The heat will gradually spread as the weld cools, but you can control that. Wet rag, water, whatever. It is not a structural weld. It only has to hold a little pin in place.
I like the TIG thing (in theory, as I have done only mine) better for that reason, and because I am currently out of oxygen, acetylene, and have no 1,100 deg solder.
it would work fine. just a little more 'cleanup' work.
TIG is just nicer because of the control factor. Even a stick welder would put metal on the spot, but I would never try that myself. I am a horribly sloppy stick welder. Both MIG and stick will get it a hair hotter, but nothing worth writing home about.
Is it done yet?
Is it done yet?
