Colt M1911 slide to frame fit

Chris_B · February 4, 2010, 12:49 PM

I have an old (1918) Colt M1911

The frame to slide fit is a bit loose. That got me thinking

What is involved with tightening the slide to frame fit on a 1911? What do they do to tighten that up?

Idahogunsmith · February 4, 2010, 01:52 PM

Usually some slide crimping tool and the frame is usually peened over with set punch design for this purpose. But be careful and buy a few gauges, that are close to the outside dimension of your frame rails. A few words of caution "go slow" remember this if you over tighten that means your have to lap, sand,polish, machine the high spots. With the rail punch, you can actually ruin a gun, if excess force is applied it can actually split the rail from the frame. Be sure to support the mag well before starting the rail option. A good book if you do not have one is written by Jerry Kuhnhausen, colt 45 automatic goes it to lengths about the how to do. I'm a licensed gunsmith and I don't tighten slides or rails. It requires really good vise or a press to squeeze down the harden slides.

Best bet, get the book read it front to back, and then ask your self this question, do you have the tools? If not get it to some one who does.

Slopemeno · February 4, 2010, 01:56 PM

Something to also remember is vertical lockup makes a huge difference in accuracy. A properly fit aftermarket barrel (I like Clark) will make your otherwise stock 1911 shoot great.

SilentHitz · February 4, 2010, 02:06 PM

Quote:

Best bet, get the book read it front to back, and then ask your self this question, do you have the tools? If not get it to some one who does.

Excellent advice! I've done a few of these, and the right tools are a MUST have...the rear of the slide where the safety notch is can easily be damaged, ( don't ask lol ) thankfully I learned using one of my old 45s.

Quote:

I have an old (1918) Colt M1911

Personally, I would not do this pistol, I would leave the old horse in her condition, or get someone who restores old 1911s to do the job...but that's just me.

Idahogunsmith · February 4, 2010, 02:16 PM

I agree with Slope, and go oversized after market barrel or even welding up you hood and the feet, my term for the lugs that contact the slidestop when the gun is in batter slide closed ready to fire. The colt barrels are high quality not like some of the others. Hers is a short list of barrels. I have used Colt, Clark, Kart, Hawk, Briley. all make over sized barrels. If you own a file and have patience these barrels work extremely well. A few words of advice, use a black marker or blue dykem, both are easy to see and remove When fitting the barrel to the slide it should snap in place and out. Then using a polish wheel polish the hell out of the hood. When recutting the lug with a hand cutter use the small cutter with the longest link first. That way if you picked the wrong link, you will still be able to fit the lugs to the proper link. Measure you slide stop pin, this is the cutter diameter you will want to use. I always use a kart mock up bushing. Then fit it with a briley or What ever type the customer wants. Of course there is always more involved then simply writing it down. Go slow again, if the skill set isn't there. Most smithys have reasonable shop rates between $45-90 per hour.

I have had guns that shoot five inch groups, shoot groups in the 1.5" inch range at 25 yards Will you get ever gun to shoot like this not a chance. Most of the accuracy of a 1911 is in the barrel and the lock up. If your not shooting bullseye or some other precision sport then this works.

**Unclenick** · February 4, 2010, 02:45 PM

By all means read some books on the topic. The Kuhnhausen book has a good deal of detail. Be aware that you could farm out some operations to a properly equipped gunsmith if you didn't feel up to tackling them all on your own?

There are some other complexities to barrel fit. Fitting that barrel lock-up marries the barrel to the slide, where the sights are. That's why it has the most effect on accuracy of all the various accuracy fitting work. However, if you simply run a barrel up high enough to mate in the locking lugs without tightening the slide, some guns are loose enough that you will then have to use a link so long and link lugs cut so high that you need to reduce the back surfaces of the link lugs before the barrel will lie down in the cradle in counter battery. You may then have to file the bottom of the chamber forward and recut its feed ramp extension to prevent it overhanging the feed ramp. It should be about 1/32" forward of overlapping for best reliability.

If you are not going to invest in the tools for fitting the slide and frame, I would look at Fred Kart's Easy-Fit barrel. It has a couple of raised spots you file to achieve tight lock-up. That lets the slide sit up a little higher in solid fit so the link lugs don't have to be cut as tall and the link doesn't have to be as long. That can avoid the fit issues I mentioned in the first paragraph, if you are lucky.

The Kart will also come with a bushing you have to fit. If you can accomplish the fit of the barrel and the bushing with no alterations to the rest of the gun, you can then keep your original barrel and bushing to put the gun back in original condition should you ever want to sell it. And you will still be able to enjoy improved accuracy for your own shooting.

If you get into the tooling you will find it a gratifying activity. You will also discover, as the late George Nonte observed, there are two kinds of accuracy work; mechanical and practical. The former is barrel and bushing and any other aspect of fitting that would make the gun shoot better from a machine rest. The latter is attention the things that enable the shooter to take advantage of improved mechanical accuracy: trigger work and better sights, for example. There are tons of add-ons out there, some more worthwhile than others. Ask around before investing in one so you don't waste your money.

RickB · February 4, 2010, 04:03 PM

I'm seeing more "high end" gunsmiths either welding or installing oversize frame rails, then machining down to fit the slide. I have one gun that was fitted with a tool that looks like a tuning fork that straddles and lowers both sides of the frame. It fit really tight for a few hundred rounds, but is now (15,000 rounds) no tighter than stock.

Double Naught Spy · February 4, 2010, 07:56 PM

Quote:

I have an old (1918) Colt M1911

The frame to slide fit is a bit loose. That got me thinking

What is involved with tightening the slide to frame fit on a 1911? What do they do to tighten that up?

Why do you want to tight the slide to frame fit? As has been indicated, that isn't where the accuracy of a gun comes from. As long as your barrel locks to your slide properly and consistently, then the barrel will be aligned with the sights consistently (assuming you have the gun properly sighted). Since you aim with the sights, whether or not the slide is a bit loose on the rail doesn't really matter.

Chris_B · February 4, 2010, 08:19 PM

Hi guys. Thanks for all the replies and suggestions

I do want to mention:

I did not say that I was going to tighten the fit personally, or even that I was going to have any work at all done on my M1911 made in 1918. I just asked what was involved; I am interested in knowing

I really do appreciate the words of caution and general gunsmithing advice though. The slide is a 'little' sloppy. It's an old pistol. My M1911A1 made in the 21st century has less slop, but not a heck of a lot less

edit-

Unclenick in particular- thanks for the reply, that also was something I was curious about- barrel to slide. I had been just swapping parts back and forth between my Colt 1911 and my non-Colt 1911A1 and marveling that all the parts just fit no matter which pistol frame or combination of parts I used, then I started thinking, well, what if they didn't fit? What does a gunsmith do to correct that?

edit2:

"I would leave the old horse in her condition, or get someone who restores old 1911s to do the job...but that's just me"

me as well! I looked at Doug Turnbull's website. Holy crap, what a talented group. Holy crap, what a lot of money!

Chris_B · February 4, 2010, 08:28 PM

Oh, I suppose after all that, I kinda owe you guys photos, for helping me out.

My entire Colt collection- "UNITED STATES PROPERTY" marked M1911 (1918) and commercial Model of 1903 (1920). A guy could get addicted to old Colts if he's not careful

dcody40 · March 11, 2010, 09:51 AM

Some of the pro's would strip the slide down and put it in a large padded
vise, and squeeze it closed a bit at a time, then trial fit and squeeze again if needed, but with this old horse, I'd leave it and just enjoy it.

I have some wobbly slide to barrel fits, with a good fitted barrel and correct link, and bushing, that can shoot (handheld) a quarter sized groups all day

or unless I start getting tired. Oh that's at 7-10 yards handheld in a weaver style hold.

Regards.

Duane USN/ret..

Scorch · March 11, 2010, 03:18 PM

FWIW, I never tighten rails on a frame any more. Most accuracy gain is in the proper fitting of the barrel and barrel bushing and in timing the action. The rest is in a good trigger. I have seen more than one 1911 ruined by well-intended people who thought peening the rails would fix accuracy issues. That "trick" of clamping slides in a vise will ruin a slide.

Your 1911 irreplaceable, I would not even touch it.

Chris_B · March 11, 2010, 05:25 PM

Hi guys

Like I've said several times; I am not going to do this work or have anyone else do it either. I was curious as to how it would be done, since this slop existed.

**Unclenick** · March 11, 2010, 06:16 PM

I think you'll find most of the slide narrowing vice jaws were used early on when slides were soft. The basic procedure involved squeezing, then hitting the vice anvil with a deadblow hammer to cause the steel in the slide to tend to take a set. It's not easy to bend a modern one, though. Often, it wasn't necessary. If you wanted a tight slide you peened the frame rails and they usually spread out enough to reach the ways in the slide anyhow.

The main reason for doing the slide fit was for use with red dot sights that mounted to the frame. In that circumstance you need the slide tightened to keep the barrel position registered with respect to the frame.

If you ever want to build a 1911 with a tight slide to frame fit, the easiest route is to buy a Caspian match slide and frame set. They are pre-machined to within a couple thousandths, as I recall? I think they also sell a frame with oversize rails you can file and lap to fit any slide.

drail · March 13, 2010, 01:01 PM

If the barrel locks up consistently and snugly in the slide and the sights are mounted on the slide the gain achieved from tightening the slide to frame fit is barely measurable and not really significant in a gun that will be fired by human hands. I have personally clamped 1911s that rattled into a Ransom Rest and watched them chew the center out of the X ring. The owners always found it hard to accept that their gun was more accurate than they were.

Chris_B · March 13, 2010, 06:43 PM

I can believe it. Firearms usually shoot better than the owners. Here's my barrel on that M1911

I'm not saying I'm a pro marksman but I can shoot pretty fair sometimes. Only modification was diffrent grips that don't let my hands slip. 33 feet, offhand, with the last 8 rounds of 50 that I took with me. Not shabby for a pistol that's 92 years old

February 4, 2010, 12:49 PM	#1
Chris_B Senior Member Join Date: February 9, 2007 Posts: 3,101	Colt M1911 slide to frame fit I have an old (1918) Colt M1911 The frame to slide fit is a bit loose. That got me thinking What is involved with tightening the slide to frame fit on a 1911? What do they do to tighten that up?

February 4, 2010, 01:52 PM	#2
Idahogunsmith Junior Member Join Date: January 27, 2010 Location: Boise Idaho Posts: 9	Many things Usually some slide crimping tool and the frame is usually peened over with set punch design for this purpose. But be careful and buy a few gauges, that are close to the outside dimension of your frame rails. A few words of caution "go slow" remember this if you over tighten that means your have to lap, sand,polish, machine the high spots. With the rail punch, you can actually ruin a gun, if excess force is applied it can actually split the rail from the frame. Be sure to support the mag well before starting the rail option. A good book if you do not have one is written by Jerry Kuhnhausen, colt 45 automatic goes it to lengths about the how to do. I'm a licensed gunsmith and I don't tighten slides or rails. It requires really good vise or a press to squeeze down the harden slides. Best bet, get the book read it front to back, and then ask your self this question, do you have the tools? If not get it to some one who does. Last edited by Idahogunsmith; February 4, 2010 at 01:57 PM. Reason: puncuation

February 4, 2010, 02:16 PM	#5
Idahogunsmith Junior Member Join Date: January 27, 2010 Location: Boise Idaho Posts: 9	Barrels and such I agree with Slope, and go oversized after market barrel or even welding up you hood and the feet, my term for the lugs that contact the slidestop when the gun is in batter slide closed ready to fire. The colt barrels are high quality not like some of the others. Hers is a short list of barrels. I have used Colt, Clark, Kart, Hawk, Briley. all make over sized barrels. If you own a file and have patience these barrels work extremely well. A few words of advice, use a black marker or blue dykem, both are easy to see and remove When fitting the barrel to the slide it should snap in place and out. Then using a polish wheel polish the hell out of the hood. When recutting the lug with a hand cutter use the small cutter with the longest link first. That way if you picked the wrong link, you will still be able to fit the lugs to the proper link. Measure you slide stop pin, this is the cutter diameter you will want to use. I always use a kart mock up bushing. Then fit it with a briley or What ever type the customer wants. Of course there is always more involved then simply writing it down. Go slow again, if the skill set isn't there. Most smithys have reasonable shop rates between $45-90 per hour. I have had guns that shoot five inch groups, shoot groups in the 1.5" inch range at 25 yards Will you get ever gun to shoot like this not a chance. Most of the accuracy of a 1911 is in the barrel and the lock up. If your not shooting bullseye or some other precision sport then this works.

February 4, 2010, 02:45 PM	#6
Unclenick Staff Join Date: March 4, 2005 Location: Ohio Posts: 21,060	By all means read some books on the topic. The Kuhnhausen book has a good deal of detail. Be aware that you could farm out some operations to a properly equipped gunsmith if you didn't feel up to tackling them all on your own? There are some other complexities to barrel fit. Fitting that barrel lock-up marries the barrel to the slide, where the sights are. That's why it has the most effect on accuracy of all the various accuracy fitting work. However, if you simply run a barrel up high enough to mate in the locking lugs without tightening the slide, some guns are loose enough that you will then have to use a link so long and link lugs cut so high that you need to reduce the back surfaces of the link lugs before the barrel will lie down in the cradle in counter battery. You may then have to file the bottom of the chamber forward and recut its feed ramp extension to prevent it overhanging the feed ramp. It should be about 1/32" forward of overlapping for best reliability. If you are not going to invest in the tools for fitting the slide and frame, I would look at Fred Kart's Easy-Fit barrel. It has a couple of raised spots you file to achieve tight lock-up. That lets the slide sit up a little higher in solid fit so the link lugs don't have to be cut as tall and the link doesn't have to be as long. That can avoid the fit issues I mentioned in the first paragraph, if you are lucky. The Kart will also come with a bushing you have to fit. If you can accomplish the fit of the barrel and the bushing with no alterations to the rest of the gun, you can then keep your original barrel and bushing to put the gun back in original condition should you ever want to sell it. And you will still be able to enjoy improved accuracy for your own shooting. If you get into the tooling you will find it a gratifying activity. You will also discover, as the late George Nonte observed, there are two kinds of accuracy work; mechanical and practical. The former is barrel and bushing and any other aspect of fitting that would make the gun shoot better from a machine rest. The latter is attention the things that enable the shooter to take advantage of improved mechanical accuracy: trigger work and better sights, for example. There are tons of add-ons out there, some more worthwhile than others. Ask around before investing in one so you don't waste your money. __________________ Gunsite Orange Hat Family Member CMP Certified GSM Master Instructor NRA Certified Rifle Instructor NRA Benefactor Member and Golden Eagle

February 4, 2010, 08:19 PM	#9
Chris_B Senior Member Join Date: February 9, 2007 Posts: 3,101	Hi guys. Thanks for all the replies and suggestions I do want to mention: I did not say that I was going to tighten the fit personally, or even that I was going to have any work at all done on my M1911 made in 1918. I just asked what was involved; I am interested in knowing I really do appreciate the words of caution and general gunsmithing advice though. The slide is a 'little' sloppy. It's an old pistol. My M1911A1 made in the 21st century has less slop, but not a heck of a lot less edit- Unclenick in particular- thanks for the reply, that also was something I was curious about- barrel to slide. I had been just swapping parts back and forth between my Colt 1911 and my non-Colt 1911A1 and marveling that all the parts just fit no matter which pistol frame or combination of parts I used, then I started thinking, well, what if they didn't fit? What does a gunsmith do to correct that? edit2: "I would leave the old horse in her condition, or get someone who restores old 1911s to do the job...but that's just me" me as well! I looked at Doug Turnbull's website. Holy crap, what a talented group. Holy crap, what a lot of money! Last edited by Chris_B; February 4, 2010 at 08:34 PM.

February 4, 2010, 01:56 PM	#3
Slopemeno Senior Member Join Date: January 19, 2007 Posts: 2,663	Something to also remember is vertical lockup makes a huge difference in accuracy. A properly fit aftermarket barrel (I like Clark) will make your otherwise stock 1911 shoot great.

February 4, 2010, 04:03 PM	#7
RickB Senior Member Join Date: March 1, 2000 Location: Boise, ID Posts: 8,518	I'm seeing more "high end" gunsmiths either welding or installing oversize frame rails, then machining down to fit the slide. I have one gun that was fitted with a tool that looks like a tuning fork that straddles and lowers both sides of the frame. It fit really tight for a few hundred rounds, but is now (15,000 rounds) no tighter than stock.

February 4, 2010, 08:28 PM	#10
Chris_B Senior Member Join Date: February 9, 2007 Posts: 3,101	Oh, I suppose after all that, I kinda owe you guys photos, for helping me out. My entire Colt collection- "UNITED STATES PROPERTY" marked M1911 (1918) and commercial Model of 1903 (1920). A guy could get addicted to old Colts if he's not careful

March 11, 2010, 09:51 AM	#11
dcody40 Senior Member Join Date: December 30, 2009 Location: Maryland Posts: 124	And for one more answer that nobody mentioned Some of the pro's would strip the slide down and put it in a large padded vise, and squeeze it closed a bit at a time, then trial fit and squeeze again if needed, but with this old horse, I'd leave it and just enjoy it. I have some wobbly slide to barrel fits, with a good fitted barrel and correct link, and bushing, that can shoot (handheld) a quarter sized groups all day or unless I start getting tired. Oh that's at 7-10 yards handheld in a weaver style hold. Regards. Duane USN/ret..

March 11, 2010, 03:18 PM	#12
Scorch Senior Member Join Date: February 13, 2006 Location: Washington state Posts: 15,248	FWIW, I never tighten rails on a frame any more. Most accuracy gain is in the proper fitting of the barrel and barrel bushing and in timing the action. The rest is in a good trigger. I have seen more than one 1911 ruined by well-intended people who thought peening the rails would fix accuracy issues. That "trick" of clamping slides in a vise will ruin a slide. Your 1911 irreplaceable, I would not even touch it. __________________ Never try to educate someone who resists knowledge at all costs. But what do I know? Summit Arms Services

March 11, 2010, 05:25 PM	#13
Chris_B Senior Member Join Date: February 9, 2007 Posts: 3,101	Hi guys Like I've said several times; I am not going to do this work or have anyone else do it either. I was curious as to how it would be done, since this slop existed.

March 11, 2010, 06:16 PM	#14
Unclenick Staff Join Date: March 4, 2005 Location: Ohio Posts: 21,060	I think you'll find most of the slide narrowing vice jaws were used early on when slides were soft. The basic procedure involved squeezing, then hitting the vice anvil with a deadblow hammer to cause the steel in the slide to tend to take a set. It's not easy to bend a modern one, though. Often, it wasn't necessary. If you wanted a tight slide you peened the frame rails and they usually spread out enough to reach the ways in the slide anyhow. The main reason for doing the slide fit was for use with red dot sights that mounted to the frame. In that circumstance you need the slide tightened to keep the barrel position registered with respect to the frame. If you ever want to build a 1911 with a tight slide to frame fit, the easiest route is to buy a Caspian match slide and frame set. They are pre-machined to within a couple thousandths, as I recall? I think they also sell a frame with oversize rails you can file and lap to fit any slide. __________________ Gunsite Orange Hat Family Member CMP Certified GSM Master Instructor NRA Certified Rifle Instructor NRA Benefactor Member and Golden Eagle

March 13, 2010, 01:01 PM	#15
drail Junior member Join Date: February 2, 2008 Posts: 3,150	If the barrel locks up consistently and snugly in the slide and the sights are mounted on the slide the gain achieved from tightening the slide to frame fit is barely measurable and not really significant in a gun that will be fired by human hands. I have personally clamped 1911s that rattled into a Ransom Rest and watched them chew the center out of the X ring. The owners always found it hard to accept that their gun was more accurate than they were.

March 13, 2010, 06:43 PM	#16
Chris_B Senior Member Join Date: February 9, 2007 Posts: 3,101	I can believe it. Firearms usually shoot better than the owners. Here's my barrel on that M1911 I'm not saying I'm a pro marksman but I can shoot pretty fair sometimes. Only modification was diffrent grips that don't let my hands slip. 33 feet, offhand, with the last 8 rounds of 50 that I took with me. Not shabby for a pistol that's 92 years old Last edited by Chris_B; March 13, 2010 at 07:48 PM.

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