Threading 1911 Barrel for Cone Fit Comp

[bossk95]

I'm looking at converting my 1911 to an open steel challenge gun to use sub minor loads and need to thread my barrel.  How deep do I need to cut the threads to fit the cone? I am looking at getting the EGW conversion cone and have not chosen a comp yet.

[zzt]

If you use the conversion cone you loose a lot of the benefit of having a cone comp.  When you use an actual cone comp the barrel is threaded about 1.5+" back from the muzzle.  That is a lot of threads in a lower heat area.  You will not shoot your comp loose.  If you use the adapter, the treads are inside the comp in a very high heat area.  Mine shot loose twice a year, even with using primer and Red Loctite.

 

I think you are wasting your time trying to use a comp for a sub-minor load.  You won't get the slide to cycle.  If you make it a little hotter it won't do much, plus load development will be tricky.  My 1911 Open steel challenge gun will not run on anything under 140 PF, and prefers higher.  Most Open shooters I know run around 150-155 PF in steel Open guns.  You need that much to get a good flat shooting load.

 

My home club will not allow compensated guns to be used in their outlaw matches.  So I fit a new, regular barrel in my 1911 Open so I could shoot there.  What I discovered was I could shoot my 109 PF PCC loads with almost no muzzle rise and very soft.  I'm actually considering leaving the uncompensated barrel in and shoot the same 109 PF load for SCSA Open and PCC.

 

If you want some additional flattening, have a poppel cut in your barrel with an opening in the slide to match.  Before I decided to build the 1911 Open myself, I was talking to Adam at Atlas Custom guns.  His recommendation for a minor steel gun with light factory ammo was poppels with no comp.

[bossk95]

7 hours ago, zzt said:

If you use the conversion cone you loose a lot of the benefit of having a cone comp.  When you use an actual cone comp the barrel is threaded about 1.5+" back from the muzzle.  That is a lot of threads in a lower heat area.  You will not shoot your comp loose.  If you use the adapter, the treads are inside the comp in a very high heat area.  Mine shot loose twice a year, even with using primer and Red Loctite.

 

I think you are wasting your time trying to use a comp for a sub-minor load.  You won't get the slide to cycle.  If you make it a little hotter it won't do much, plus load development will be tricky.  My 1911 Open steel challenge gun will not run on anything under 140 PF, and prefers higher.  Most Open shooters I know run around 150-155 PF in steel Open guns.  You need that much to get a good flat shooting load.

 

My home club will not allow compensated guns to be used in their outlaw matches.  So I fit a new, regular barrel in my 1911 Open so I could shoot there.  What I discovered was I could shoot my 109 PF PCC loads with almost no muzzle rise and very soft.  I'm actually considering leaving the uncompensated barrel in and shoot the same 109 PF load for SCSA Open and PCC.

 

If you want some additional flattening, have a poppel cut in your barrel with an opening in the slide to match.  Before I decided to build the 1911 Open myself, I was talking to Adam at Atlas Custom guns.  His recommendation for a minor steel gun with light factory ammo was poppels with no comp.

Ok thanks for the tip, on threading the barrel topic since I'm working on getting an open 2011 put together also, with the conversion cone would putting a set screw on the bottom do any good from keeping it from coming loose?

[zzt]

13 hours ago, bossk95 said:

Ok thanks for the tip, on threading the barrel topic since I'm working on getting an open 2011 put together also, with the conversion cone would putting a set screw on the bottom do any good from keeping it from coming loose?

 

Yes, but why bother when you can buy a one piece cone/comp combo?  If you cannot find a port pattern you like, buy a blank and have it milled out with a custom port configuration.  I did exactly that with Aircolled6racer.  He cut his custom comp ports into two Trubore blanks that I used for two Open builds.

 

The beauty of a cone comp is the increased security.  With a conversion cone you loose that.

[MikeBurgess]

on the threading depth just measure the cone you are using and thread the length of the threads in the cone plus a little bit, there is normally about a 1/2" un threaded area at the small end of the cone so you can have plenty of extra threaded area on the barrel and still have the cone cover it for a nice clean installation.

 

that said I personally would not try to thread a barrel by hand with with a die, the alignment needs to be pretty spot on for both proper lock up and comp alignment, I believe lathe is pretty much a must if you want it to turn out correctly, the risk of messing up a $200 barrel is just too high for me

[bossk95]

1 hour ago, zzt said:

 

Yes, but why bother when you can buy a one piece cone/comp combo?  If you cannot find a port pattern you like, buy a blank and have it milled out with a custom port configuration.  I did exactly that with Aircolled6racer.  He cut his custom comp ports into two Trubore blanks that I used for two Open builds.

 

The beauty of a cone comp is the increased security.  With a conversion cone you loose that.

I actually just saw the blank comps last night and decided on going that route.

[bossk95]

55 minutes ago, MikeBurgess said:

on the threading depth just measure the cone you are using and thread the length of the threads in the cone plus a little bit, there is normally about a 1/2" un threaded area at the small end of the cone so you can have plenty of extra threaded area on the barrel and still have the cone cover it for a nice clean installation.

 

that said I personally would not try to thread a barrel by hand with with a die, the alignment needs to be pretty spot on for both proper lock up and comp alignment, I believe lathe is pretty much a must if you want it to turn out correctly, the risk of messing up a $200 barrel is just too high for me

I am a tool maker so it was going to be done on a lathe regardless, I have used dies enough times to know they are useless for anything that needs to be critical.  I figured I would need to cut them a little long past what they are in the cone but how deep do I need to actually cut into the barrel? Do I need to go just enough so it threads on with slight resistance so it stays lined up properly? Every time I have cut threads on a lathe I have known the major and minor diameter I needed to cut to, I can get the minor once I have the comp in hand, I am just concerned on the actual fit of the threads.

Edited Monday at 04:24 PM by bossk95

[MikeBurgess]

36 minutes ago, bossk95 said:

I am a tool maker so it was going to be done on a lathe regardless, I have used dies enough times to know they are useless for anything that needs to be critical.  I figured I would need to cut them a little long past what they are in the cone but how deep do I need to actually cut into the barrel? Do I need to go just enough so it threads on with slight resistance so it stays lined up properly? Every time I have cut threads on a lathe I have known the major and minor diameter I needed to cut to, I can get the minor once I have the comp in hand, I am just concerned on the actual fit of the threads.

Ahh

 

I try to keep the threads to minimum depth to keep alignment as good as possible, I want to say its about .014" deep ( .017 on the compound)  but I would double check in machineries handbook, its just a .575 major dia 40 tpi thread nothing special other than its not a normal size out side of threading barrels. that said I tend to run it close by the numbers then test fit to the cone so I don't over shoot, the darn threads are so small an extra .001 makes a pretty big difference. 

 

 

 

Edited Monday at 04:44 PM by MikeBurgess

[Bwenning]

You're going to have to have the comp in hand and cut until it fits how you want it to. I recently made two comps and went until they threaded on with slight resistance, it worked out well. 

[zzt]

Very slight resistance.  Another tip:  DO NOT use Loctite Primer on the threads prior to applying Red Loctite.  If you do you will never get it threaded on and clocked before it sets up.

[bossk95]

Ok thanks for the help guys, so once I've got the barrel threaded and fit to the slide what do I need to do to install it? I know there needs to be a 1° or what ever the gap ends up being faced off the slide.  What is involved in timing it and blending/final fitting of the comp before finish reaming?

[Bwenning]

I indicated the end of the barrel level to determine the angle and then ground the end of the slide until it was about .003" below level where the comp would stop, may have been easier to determine since I have a hybrid Barrell. Once I had the comp on I checked it with feeler gauges and made adjustments until I wound up with a .005" gap everywhere. 

[Bwenning]

Here are some other in process pics of making the comps.

[Bwenning]

 

Here are some other in process pics of making the comps.

[Bwenning]

 

Here are some other in process pics of making the comps.

[Bwenning]

 

Here are some other in process pics of making the comps.

[zzt]

boss, take a look at the last issue of USPSA mag.  Bob L. from Brazos customs goes through the steps required to fit an Open barrel and slide.  It is a lot more complicated than fitting a non-compensated barrel.  Sorry, scratch that.  Your barrel is already fit.  So you trim the front of the slide back a little at a time until the comp clocks and there is .003" clearance all around.  .035" had to be taken off the front of one of my slides to fit.  The other, not so much.

 

 

[Bakerjd]

That comp looks oddly familiar. 

[bossk95]

3 hours ago, zzt said:

boss, take a look at the last issue of USPSA mag.  Bob L. from Brazos customs goes through the steps required to fit an Open barrel and slide.  It is a lot more complicated than fitting a non-compensated barrel.  Sorry, scratch that.  Your barrel is already fit.  So you trim the front of the slide back a little at a time until the comp clocks and there is .003" clearance all around.  .035" had to be taken off the front of one of my slides to fit.  The other, not so much.

 

 

It was the September/October 2020 issue for anyone else looking at this, I will definitely be reading that tonight when I have a chance, I am starting to think I might just buy a bare slide and fit everything correctly, my slide isn't machined for a reverse plug and I'm not sure about drilling and tapping my frame with how thin it is so I might just look at a bare slide and mill what I want in it.  That way I don't ruin my single stack gun at the same time

Edited Tuesday at 12:28 AM by bossk95

[zzt]

If you are afraid your receiver is too thin, consider mounting the optic on the slide.   I've done that on many guns. One competition 1911 45 has a deep scallop on the rear of the slide, just like an Open gun.  The optic is mounted directly to the slide.  I added a dovetail mounted optic to my Limited gun and used it to shoot steel challenge for two years.  Another 45 wears a dovetail mounted optic.  That one lasted 40,000 rounds before the plastic diode cover cracked and fell off.  The sight still worked.  I shoot with two guys who shoot Open major with a slide mounted optic.  Both have used the same setup for years without a problem.  All told I have six optics mounted on reciprocating slides.  All work just fine.

[MikeBurgess]

I found it worth while to start this adventure by getting a RIA 1911 builders kit of Ebay and a Foster frame from Caspian, this way I got to start from close to scratch and if I messed up a part it wasn't a $200+ part I believe the builder kit cost less than $300 and the frame was about $150. I have also used Ebay RIA barrels that go for about $70 on a few other retrofit projects on old cheep guns I owned. after doing a few this way I felt a lot better when I chucked up a real barrel in my lathe and started making cuts on a quality slide.

 

 

[bossk95]

10 hours ago, zzt said:

If you are afraid your receiver is too thin, consider mounting the optic on the slide.   I've done that on many guns. One competition 1911 45 has a deep scallop on the rear of the slide, just like an Open gun.  The optic is mounted directly to the slide.  I added a dovetail mounted optic to my Limited gun and used it to shoot steel challenge for two years.  Another 45 wears a dovetail mounted optic.  That one lasted 40,000 rounds before the plastic diode cover cracked and fell off.  The sight still worked.  I shoot with two guys who shoot Open major with a slide mounted optic.  Both have used the same setup for years without a problem.  All told I have six optics mounted on reciprocating slides.  All work just fine.

I think that's what I am going to do now is just get an inexpensive bare slide and mill an optic cut in it and fit the comp to it.

[bossk95]

10 hours ago, MikeBurgess said:

I found it worth while to start this adventure by getting a RIA 1911 builders kit of Ebay and a Foster frame from Caspian, this way I got to start from close to scratch and if I messed up a part it wasn't a $200+ part I believe the builder kit cost less than $300 and the frame was about $150. I have also used Ebay RIA barrels that go for about $70 on a few other retrofit projects on old cheep guns I owned. after doing a few this way I felt a lot better when I chucked up a real barrel in my lathe and started making cuts on a quality slide.

 

 

I might have to get a few of those and play around with them, I'm also thinking of getting a few frames and slides from JEM to play around with also.  That will probably be a ways down the road though