blacklab Posted September 9, 2015 Share Posted September 9, 2015 I have a 6" barrel for a 1911 9mm. I was thinking about cutting it down to 5.75" and putting a 578x28 thread on it for a comp. How hard is it to cut and thread a barrel? It seems fairly simple, am I missing something? Is there any tricks to the trade that I don't know about? I have access to a lathe to re crown the barrel. Is there anything else I should know? Thanks. Link to comment Share on other sites More sharing options...
kneelingatlas Posted September 9, 2015 Share Posted September 9, 2015 I use a chop saw and a hand threader: I eyeball the muzzle square, then polish it with sand paper down to 2500 grit, it's always worked really well for me, I've probably done over a dozen at this point. Link to comment Share on other sites More sharing options...
blacklab Posted September 9, 2015 Author Share Posted September 9, 2015 Cool. Thanks for the info. Do you do anything with the crown? Link to comment Share on other sites More sharing options...
kneelingatlas Posted September 9, 2015 Share Posted September 9, 2015 Nope, just square. Link to comment Share on other sites More sharing options...
Aircooled6racer Posted September 9, 2015 Share Posted September 9, 2015 Hello: I use a lathe to do mine. That way it is square with the bore. Thanks, Eric Link to comment Share on other sites More sharing options...
blacklab Posted September 9, 2015 Author Share Posted September 9, 2015 Thanks for the help guys. Link to comment Share on other sites More sharing options...
Toolguy Posted September 9, 2015 Share Posted September 9, 2015 I use a close fitting brass plug in the chamber, held in the lathe chuck and a live center in the muzzle. Single point thread to a little oversize, then thread a die on to finish size. That way the thread is exactly parallel and concentric to the bore every time. The hood of the barrel against a chuck jaw is the driver to turn the barrel. Link to comment Share on other sites More sharing options...
MrPostman Posted September 9, 2015 Share Posted September 9, 2015 I use a close fitting brass plug in the chamber, held in the lathe chuck and a live center in the muzzle. Single point thread to a little oversize, then thread a die on to finish size. That way the thread is exactly parallel and concentric to the bore every time. The hood of the barrel against a chuck jaw is the driver to turn the barrel. Great info! Link to comment Share on other sites More sharing options...
fastshooter03 Posted September 30, 2015 Share Posted September 30, 2015 Sure putting threads on is simple...making them good is another matter. If you have access to a lathe, first make sure you have a good barrel by indicating the OD and ID to see if they are concentric at both the chamber and muzzle. I've seen a few now from very well known manufacturers that had a good chamber end but bad muzzle. Basically the bore's going one way and the OD another..... It's REALLY important to get the thread perpendicular and concentric to the bore. I don't recommend starting with a die if you don't have to. I would also have the mating piece in hand so you don't take the threads too deep and never force the comp on or it might gall the threads. Nick Link to comment Share on other sites More sharing options...
Can Posted September 30, 2015 Share Posted September 30, 2015 (edited) Sure putting threads on is simple...making them good is another matter. If you have access to a lathe, first make sure you have a good barrel by indicating the OD and ID to see if they are concentric at both the chamber and muzzle. I've seen a few now from very well known manufacturers that had a good chamber end but bad muzzle. Basically the bore's going one way and the OD another..... It's REALLY important to get the thread perpendicular and concentric to the bore. I don't recommend starting with a die if you don't have to. I would also have the mating piece in hand so you don't take the threads too deep and never force the comp on or it might gall the threads. Nick technically you cant measure concentricity with an indicator on a lathe, your measuring either runout , or total runout it takes a special gauge to measure concentricity kind of, or preferably a cmm. but that doesn't really matter, what your suggesting is good and correct information. i have a little trick, when you single point threads, you know the dial the laythe has that spins around for multiple lead threads? when you lock the carriage onto a number (usually 1- 4, or a-d) never unlock it....cut the threads in, then back the cross slide out so your cutter is not touching the material, then run the motor backwards to get the tool back to your starting place. more threads get messed up by not getting back on the same number than anything else in my experience....so just never unlock from that number and you can't muck it up. Edited September 30, 2015 by Can Link to comment Share on other sites More sharing options...
Toolguy Posted September 30, 2015 Share Posted September 30, 2015 I just use the same number on the dial for all threading. Then you don't mess up either. Link to comment Share on other sites More sharing options...
Flash74 Posted September 30, 2015 Share Posted September 30, 2015 For $65 you can send your barrel to Adco Firearms for a cut and thread. I have had several rifle and pistol barrels threaded by them since they are local. Everything turned out great except for one issue, but they quickly made it right. Link to comment Share on other sites More sharing options...
caspian guy Posted September 30, 2015 Share Posted September 30, 2015 Never unlocking the half nuts like can is suggesting is also a good idea if your lathe is less than great (cheap or worn). I find the threads seem to tun out nicer in that situation with that method. On my monarch it doesn't seem to matter that much so I do it like tool guy suggests. Link to comment Share on other sites More sharing options...
Can Posted October 1, 2015 Share Posted October 1, 2015 I just use the same number on the dial for all threading. Then you don't mess up either. your way doesn't really work that well, or you wouldn't need to finish the threads with a die nut. you could cut them to finish size with the laythe, and thread wires. that said, the very best , most accurate, strongest threads are not cut threads...they are ground with a grinder then thread rolled. most aviation threads are done this way. i ran a monarch lathe but it didn't have a reversible motor. it was very old. it was a monster of a lathe though. Link to comment Share on other sites More sharing options...
Toolguy Posted October 1, 2015 Share Posted October 1, 2015 (edited) My way works just fine. I have single pointed hundreds of threads to finish size that way. Using a split thread die that is adjusted to the size I want just makes it quicker and easier to hit the same exact size without having to measure every one. If you're doing a bunch all at one time, you just get the first one to size, then do the rest of them to the same number on the dial or DRO. The ones I have a die for I only do occasionally so it cuts down on the measuring to finish with a die, no worries about going undersize. I've been a tool & die maker for 40 years. I have it pretty well figured out at this point. I have years of time in on several kinds of every machine in a toolroom, manual and CNC + tool & cutter grinding, heat treating and all forms of welding. Not bragging, just explaining - I do know what I'm talking about. Edited October 1, 2015 by Toolguy Link to comment Share on other sites More sharing options...
Can Posted October 1, 2015 Share Posted October 1, 2015 I concede I've not made that many threads. mostly we send them out to be ground and rolled. i'm mostly a mill guy. you probably have your process down just fine after 40 years of it. im also kind of a prick if you hadn't noticed. Link to comment Share on other sites More sharing options...
Toolguy Posted October 1, 2015 Share Posted October 1, 2015 I try to share what I know (machining and S&W revolvers) and learn from others what I don't know (most everything else). I have found that I can learn something from nearly anyone. That means that there is a place on the Forum for everyone. I try to learn something new every day. I believe any knowledge adds something to one's quality of life. This is the information age. You simply pick up what you want as it goes by. And it's all free for the taking! What a deal! Link to comment Share on other sites More sharing options...
MrPostman Posted October 2, 2015 Share Posted October 2, 2015 I try to share what I know (machining and S&W revolvers) and learn from others what I don't know (most everything else). I have found that I can learn something from nearly anyone. That means that there is a place on the Forum for everyone. I try to learn something new every day. I believe any knowledge adds something to one's quality of life. This is the information age. You simply pick up what you want as it goes by. And it's all free for the taking! What a deal! Amen! The internet is awesome! So much knowledge at your fingertips Link to comment Share on other sites More sharing options...
blacklab Posted October 3, 2015 Author Share Posted October 3, 2015 Looks like there is a lot of complex ways to thread a barrel. I went with Kneelingatlas's way, cut and thread by hand. Buts it's not a 5k build, It's a experiment. I just want to build my own gun to see how hard it is. At this point I don't think I will ever try it a gain. I now see why a good pistol smith is pricy and has a backlog. Link to comment Share on other sites More sharing options...
Chips0410 Posted October 11, 2015 Share Posted October 11, 2015 This is how I do all my threading and anything else I need to do .. Make comps and other odds and ends ... Link to comment Share on other sites More sharing options...
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