Expert Advise - Barrel Fit

[Hill]

I have a new SS gold Cup that's as yet unfired.

I have an unfired Ed Brown "drop in" barrel that I bought for another project and ended up not using.

In checking out the new Colt's fit I find .005" side clearance of the barrel hood, original NM barrel. The slide notch is .390", the barrel tang (whatever it's called) is .385".

The Ed Brown barrel, which by the way DID drop right into a 70 series slide that I have, measures .420" for tang width, so it needs fitting into the Gold Cup if I use it.

I can do a closer fit than the NM barrel was fitted to but do you think I'll 1) gain accuracy, 2) lose reliability of function if I bring that fit in at say - .002" ?

The fit of the Brown barrel into the notch where the slide pin stop acts on the barrel would be closer too - but I want to leave that part of the question until a choice about the tang fit is made.

I don't have enough time on 1911 fitting myself and this seems like a heck of a good place to ask a question like this. So is this worth pursuing, or is it a case of Colt knows best?

[Hawkmoon]

Why don't you shoot the new Gold Cup a bunch, and then if you think the accuracy is sub-par and you'd prefer to muck around rather than just send it back to Colt -- fit the other barrel to it then. I can find no logic to the notion of fixing a "problem" that may not even exist.

[Joni Lynn]

The hood fit is important but the fit of the barrel feet is more important as is the bushing fit. My best shooting 1911 has a sloppy fit hood thanks to me allowing someone to do the work that didn't have a clue. I had someone that knows what to do fix the problems and it shoots great even with a generous gap on the hood. It does irk me though to have that gap, even if I'm the only one that knows it's there.

[Hill]

Why don't you shoot the new Gold Cup a bunch, and then if you think the accuracy is sub-par and you'd prefer to muck around rather than just send it back to Colt -- fit the other barrel to it then. I can find no logic to the notion of fixing a "problem" that may not even exist.


Yeah, I know your point about 'if it works, don't fix it' well.

It's only that I've got the pistol apart to do several things, and I've got the barrel from Ed Brown sort of burning a hole in my pocket. That and I do prefer to "muck around" rather than send anything back to the maker. I figure that they already took the best shot they'll ever take for the price break on their product.

I asked about the hood first because I'm not sure of the relative importance of the .005" fit. I thought that if someone who fits barrels said ".005" is just right" I'd leave the pistol as found.

Lynn, the fit of the feet was going to be my followup. On that, the frame notch is .364" wide, the Colt NM feet are .356" wide, and the Ed Brown is .361" wide.

It's clear that the Brown barrel would make for a closer fit in both areas if I do well but where does too tight to function reliably rear it's ugly head?

The STI provided "visual pistol" animation has become my favorite movie.

[Joni Lynn]

If you look around the forum you'll probably find the info you need on barrel fitting and tools required.
Good luck!
Remember if you fit it too tightly to function 100% you can always work on it a 'lil bit more until it suits you. However if you take off too much metal you'll have a really rough time putting it back on.

[niemi24s]

FWIW, for a U.S.G.I. M1911A1, the total clearance for the feet/feet slot works out to 0.0075 +/- 0.0045 inch. Feet width = 0.362 - 0.004 inch and slot width = 0.365 + 0.005 inch.

Don't recall reading any barrel fitting material that mentions anything about how close the fit in this area should (or shouldn't) be.

Highly recommend you shoot it lots before deciding what to do. For all you now know, it may give 1 1/2" groups at 50 yards with match-grade SWC ammo. While I can understand the urge to do something with the Ed Brown barrel, why risk messing up what may be (for all you know) the most accurate 1911 ever to depart the Colt factory?

My shooting buddy's got a tack-driving Gold Cup that (when shaken) rattles like a can of rocks!

[1911Tuner]

There is much, much more to barrel fit than hood to slide recess clearance. So much more...

[Hill]

There is much, much more to barrel fit than hood to slide recess clearance. So much more...

Hi.
Yeah, there is. It's only that with the Gold Cup I expected the new pistol to have a 'snap' together kind of fit.

So all I meant to ask about is whether the immediate clearances as I've found them in the Colt are something that would be improved upon before going ahead with assembling the gun by someone who's business it is to build up good shooting guns.

I've done some of this work. Accurizing bullseye guns paid part of my college days bills. I used to weld up hoods with the barrels buried in a can of wet beach sand, then flip the barrel over and weld up the camming surfaces and work them all back by hand. I used plastiguage to measure and then silver soldered shimstock inside the slide grooves to hold the barrel down (as I used to call it - a method learned from a close examination of a Bob Chow accurized gun although no doubt his techniques were more sophisticated than mine). Squeezed slides and never cracked one, and banged merrily on the frame rails until I had to use a mallet to get the slide moving again so I could lap it to a fit. Charged $75.00 for each job. The going rate was about $150. although you payed a lot more for a Chow or Clark built gun.

[Hill]

FWIW, for a U.S.G.I. M1911A1, the total clearance for the feet/feet slot works out to 0.0075 +/- 0.0045 inch. Feet width = 0.362 - 0.004 inch and slot width = 0.365 + 0.005 inch.

Don't recall reading any barrel fitting material that mentions anything about how close the fit in this area should (or shouldn't) be.

Highly recommend you shoot it lots before deciding what to do. For all you now know, it may give 1 1/2" groups at 50 yards with match-grade SWC ammo. While I can understand the urge to do something with the Ed Brown barrel, why risk messing up what may be (for all you know) the most accurate 1911 ever to depart the Colt factory?

My shooting buddy's got a tack-driving Gold Cup that (when shaken) rattles like a can of rocks!

I didn't know those GI specs., Thanks. Isn't it something that Colt makes the feet width on a Gold Cup, supposedly the match ready version of their commercial pistols very nearly outside the low GI specification and the slot just .001" under the nominal GI specification? Wow! Makes me wonnder if I wasn't sold a bill of goods, or maybe a lemon.

Yeah, I'm gonna' put it together now with it's own barrel. At least It'll look better than when it came from the box.

http://i130.photobucket.com/albums/p263/twagger/guns/SSGC2.jpg

[Hawkmoon]

What's important is how it shoots, not what the specs are on paper.

I respectfully suggest that you sell the Gold Cup before you start changing it, and buy a Les Baer or Ed Brown to go with your barrel.

[1911Tuner]

and banged merrily on the frame rails until I had to use a mallet to get the slide moving again so I could lap it to a fit.

Ouch. Your file is your friend. Become one with your file...

silver soldered shimstock inside the slide grooves to hold the barrel down (as I used to call it -

Fascinating. Wonder why he deliberately reduced vertical lug engagement.

[Hill]

Ouch. Your file is your friend. Become one with your file...

Fascinating. Wonder why he deliberately reduced vertical lug engagement.

I think it was common practice back then to jam the barrel into battery both from the bottom by the link and from the top to force a firm location of both the barrel and the slide. You've seen a Bomar "accuracy rib"? It had a little gizmo that could be adjusted downward by the owner and had the same effect as the shimstock I mentioned - located the barrel while taking some lost motion from the slide/frame but only in lockup. There were quite a few bullseye shooters who were proud of their Bomar tuners.

There was no such thing as CNC machining in those days and I'd say the understanding of the in battery condition has developed since Bob Chow time. . also, I know that Bob Chow would take people's guns in used condition for a while. So maybe the one I got to look over had needed the shim work more than others, I really don't know. Later I heard that he insisted on new guns, and a shooter could bring his own or he could buy it in the Chow gunshop. I don't know if he had the shop when he started working guns. Last I heard anything about him was 1981 when someone told me the wait time for one of his guns was up to two years.

He was 77 years old when I met him at a match in the Presidio, San Francisco, and he was still competing. I won a five buck coupon that day redeemable only at his store.

[1911Tuner]

I think it was common practice back then to jam the barrel into battery both from the bottom by the link and from the top to force a firm location of both the barrel and the slide.


Actually...it was a quick'n'dirty method to center up the firing pin with the chamber instead of lowering the frame rails and refitting to bring the slide's installed height into spec. Considered to be an accuracy enhancing tweak, it worked okay with powderpuff ammo common to the Bullseye game in those days. The shooters didn't really punish the guns much, and the ammunition was gentle...so there was no pressing need to place the brunt of the forces low on the locking lugs.

It changes with full-power or "Major Power" ammunition required by IDPA and IPSC.
The lugs set back horizontally from the battering pretty quickly under the stresses of firing 50,000+ rounds of major power ammo per year.

Then...Some of smiths who build the precision Bullseye/Match pistols discovered that there isn't enough difference in potential acuracy with a perfectly centered pin strike and one that's .010 inch off in the vertical plane. It literally required a Ramsom rest on a heavy bench and exceptional ammunition to see the difference...and even then, there wasn't much. Not enough to worry about, at any rate.

Same goes for tight, horizontal contact between barrel hood and breechface. No practical difference between one that jammed the barrel forward and one with .003 inch of clearance with the barrel held forward. More important is close, even clearance at the sides of the hood and full, even support on the bottom between the slidestop pin and the lower lug.

Yeah...We've come a long way, baby. FWIW, I don't build pistols like these. Much too tedious, y'know... ;)

[Hill]

OK. I don't want to come across as thinking I know all that much or have much experience. I've just always liked messin' with guns.

Yep, 3.5 grains of bullseye behind home cast 200 gr. SWC was the food. In fact I avoided hardball ammo in order to keep from getting an incurable flinch.

As you can see I've just come to this place and I've spent a lot of time reading because there's so much more to know then was available then. There was an NRA pamphlet describing how to accurize the 1911, and some more info in a book titled "Handgun Competition" by Maj. George C. Nonte that devotes some 28 pages to accurizing, and another 11 pages on 'tuning for reliability'. Not sure if much more than that existed.

So to find people here, and in particular you here, posting freely about the workings of the pistol is like finding a goldmine to me. Did I say Thank you? Well, there.

[Hill]

More important is close, even clearance at the sides of the hood and full, even support on the bottom between the slidestop pin and the lower lug.

Yeah...We've come a long way, baby. FWIW, I don't build pistols like these. Much too tedious, y'know... ;)

Reading your last again, the bit about the close side fit of the hood goes to the question that opened this thread.

Colt left .005" - it looks evenly split though I don't have a guage that fits in that crack, but I was asking is .0025" per side (assuming an even lug fitting) too much, as I have a barrel I could fit tighter than that. I even still have my old Brownell's handcrank lug cutter that cost $13.00 as best I can recall.

Tedious is right; so far my wife doesn't call me tedious. She's gotten hard of hearing - more so than I thought, I guess :D

[1911Tuner]

I've just always liked messin' with guns.

Yeah. That's how it starts out. Then it gets to be habit...then obsession. Therein lies madness. Ask me how I know... :D

but I was asking is .0025" per side (assuming an even lug fitting) too much, as I have a barrel I could fit tighter than that

.0025 per side is actually a pretty close fit for a factory-assembled gun. If the lower lug is evenly and squarely supported by the slidestop crosspin, I'd say let it be...assuming that the upper lugs are getting into the slide at least .045 inch deep and you've got at least two bearing evenly in the horizontal plane...preferably the first and second lug, with the rearmost one being the first.

Of course, static headspace dimension is also a factor, as is fore/aft play between barrel and slide with the barrel vertically engaged.

So many little things that add up to make an accurate pistol, you can't really determine the potential by gauging, measuring, or eyeballing any single one. I've seen barrels that were pretty sloppy that were surprisingly accurate, and I've seen a few that...on initial inspection...seemed to be exceptionally well-fitted that were dogs.

Take a good-quality match-grade barrel, and fit it carefully...not loose, but not too tight. Use good ammo, and it'll likely be wicked accurate. I've slapped in a few Kart Easy-Fit barrels in 30-45 minutes that'd cut a 7-shot bug-hole at 25 yards...and I've spent several hours on full hard-fit barrels that didn't do a whole lot better.

The guns that really will stay inside an inch at 50 yards are precision efforts...and the cost reflects it. It's like an old local engine builder used to tell the young lads in search of a fast car. "Speed costs money. How fast can you afford to go?"

[kcshooter]

What's important is how it shoots, not what the specs are on paper.
On the last one I did, about 2 months ago, I don't even know what the measurements are. It was all done off the original specs and then slowly filed by feel and fit. It was a full build, all fresh parts, and it's one of the best shooters I've made so far.
Not that that's a good idea, but if it works...

[1911Tuner]

Not that that's a good idea, but if it works

Hey! Some of the best all-around shooters I ever tweaked for myself, I did by the seat of my pants, and only checking/adjusting for horizontal upper lug engagement. Scraped the lower lug in with the edge of a knife blade, and did the final fit with a length of .195 drill rod in a cordless drill with 5 micron lap and DuPont 606 S polishing compound.

Now, about that mallet... :D

[Hunter]

I have to wonder have you shot the Gold Cup yet? Is it horrible inaccurate or unreliable?
Bear in mind the Gold Cup Trophy is not a custom bullseye pistol but then again it don't cost $4000 either.
Mine has served me well through IDPA matches and many range sessions.
Before I began fixing my pistol I would be sure it is broke.

[Hill]

OK, I really appreciate the opportunity to bounce this around and I've learned a few things too, and that's all good.

The pistol is the first new one I've bought since 1979 and with serial numbers on the outside of the box these days I took it home before even seeing it. After opening the box at home, I was appalled at how ugly it was. It didn't look like them little website pictures, so I tore it down to make it more to my liking. I had a blued magwell and spring housing, some nice magwell fitted grips, a blue grip safety sitting around, and I'm equipped to buff steel here.

It looks nicer now. The powdery parts of the finish are smooth, the polished sides are really polished now, and the trigger, safety, slidestop, bushing, and spring retainer have a high sheen too. I even shaped the safety by hand to make it more smoothly cut like the old Colt commercials had. I like the blued back end and magwell on it too. It's still stainless, but it's a nice looking gun now. I might muster the nerve to try checkering the front strap one day, but not this time.

While apart though I tried the fit of this drop in fit Brown barrel and went "Hmmm". You'all know the rest.

I see that the barometer has dropped like a stone this morning. It's raining and they say it'll get worse today. Maybe I'll take the gun out back and fire it today, maybe not.
Soon though, 'cause I'm through messing with it.

Now, I've got this old Star B with a lousy finish. It doesn't know it yet but I'm thinking it looks like a fine sacrificial goat, and that's an improvement right there. :)

[Hill]

Ready to go:

http://i130.photobucket.com/albums/p263/twagger/guns/SSGoldCup.jpg

As received:

http://i130.photobucket.com/albums/p263/twagger/guns/ss_GOLDCUP_ASIS.jpg

Next victim:

http://i130.photobucket.com/albums/p263/twagger/guns/starB.jpg

[1911Tuner]

Purty work, Hill! Me? I build ugly guns. I've never even had one of my own refinished afterward. :D

[Hill]

I'm gonna' make the Star slide flat on top and then see iff I've got a cutter that'll serrate it, surface grond the sides of both frame and slide, try undercutting the grip and checker that, and then see what about getting the pistol tighter. Far as I know there's no supply of aftermarket parts for those but it's got a good bore and trigger and I've got a Novak non adjusting sight that's extra and a few dovetail cutters..
I've wanted to try my wife about using one of the kitchen ovens for gunkote baking too.
That Star is a throwaway piece of junk to me - good candidate for experiments.
The days of buying 1911's for $29.95 each are long gone. When you could buy them in magazine ads I used to pester my father to let me get some, but he had been near gutted at Tarawa and wanted nothing to do with war in the house.

[1911Tuner]

The days of buying 1911's for $29.95 each are long gone.

Whoa! You do go back a long ways. I remember USGI pistols that came in the mail for the princely sum of 12 bucks plus shipping.


[quote=Hill]I used to pester my father to let me get some, but he had been near gutted at Tarawa. quote]

Semper Fi!

[Hill]

Just turned 59 the other day. As a kid I pored over those little ads in the back of Popular Mechanix and the like. When you said 12 bucks it rings a bell, and I DO remember seeing them for $17.95. Rifles a little more, real Nazi helmets for less than ten bucks. There was surplus stuff from the war everywhere. If we could just invent a time machine that'd take a train, a hundred or so boxcars, and us back to 1955 with a bunch of money we could live out our lives in sure luxury,---or maybe I'd just stay there. :D

[1911Tuner]

Hill...I think M1 Carbines were $17.50 plus $2.50 for shipping. Nice ones, too! My ol' man got two USGI pistols for 14 bucks apiece, including shipping. One was a pretty nice Union Switch, and the other one was a Colt. A year later, he got a pair of Rands and thought it was awful that the price had gone up a buck.

Those were the days. Oh! Yes...

[saltydog]

As kids, we could also walk home from school w/o our parents worrying much more than having to, tactifully, explain why I coundn't keep the stray dog that 'followed me home'.

salty.

Sorry, (kinda), sorta off topic..coundn't resist. Wally told me to say that.

sd.

[niemi24s]

All this reminiscing is getting me weepy-eyed and sentimental. STOP IT! :D

[1911Tuner]

All this reminiscing is getting me weepy-eyed and sentimental. STOP IT!

Hey! Salty started talkin' about dogs. Blame him for makin' ya go all misty.

[Hill]

Me too, but it's your link that gets me with the pretty Collies - if I was on that coast I'd probly already have one on the way home.

Well, the gun shoots. It worked fine I mean, although I outshot myself when I fired my SA XD Tactical .45 acp right after warming up the new GC. The sight was 14 clicks high out of the box - I should have caught that before I left home because it LOOKED like it was cranked up. Maybe Colt paper trains their guns with squids, primer only. I don't know.

I think it's too early on to tell whether it's accurate mostly because I was shooting up a bunch of steel case hardball ammo from some foriegn country - maybe Selior&Bott, something like that. I've had a couple hundred rounds of it around here for almost ten years. Also, it's been several years since I fired pistols at targets. Had to get my dominant eye cataract fixed first. :)

Nothing broke and I don't see any odd looking wear or strike marks. I'd honed all of the fingernail catches out of the gun while it was apart so it runs slick.

[kcshooter]

I think M1 Carbines were $17.50 plus $2.50 for shipping.
two USGI pistols for 14 bucks apiece, including shipping. One was a pretty nice Union Switch, and the other one was a Colt. A year later, he got a pair of Rands and thought it was awful that the price had gone up a buck.When you said 12 bucks it rings a bell, and I DO remember seeing them for $17.95The days of buying 1911's for $29.95 each are long gone

I don't know why I'm wasting my time tinkering on these stupid guns, I'm goin' back to work on the time machine!

[Joni Lynn]

**Please** let me know when you've got it up and running! :D Thanks!

[1911Tuner]

I'm goin' back to work on the time machine!

Take a breath, bro. This Rand's fer yew... ;)

http://i40.photobucket.com/albums/e243/1911Tuner/45RR.jpg

[Hill]

Tsk! That old Thang?? :)

Back to topic........I've found that the left foot of the barrel lug makes contact with the bottom of the frame notch. It seems to be kicking the barrel over so that the right front of the lug wears on the right side of the notch and the rear of the left lug contacts the left side of the notch. I think stoning about .005" off of the tip of the lug foot will cure that.

The overall width of the barrel foot is .354" and the width of the notch in the frame is .361" measured at the lower most narrow point, well away from the machined bevel at the top of the notch.

I've pin guaged the slidestop hole to be .2005" (.201" won't enter the hole) while the slidestop pin measures an undersize .197".

There's still the lateral .005" between the barrel hood and slide notch.

So, in my book, I'm looking at a lot of slop in this new pistol's fitting. Ain't that a fine how do you do?


In a quick test firing the pistol was obviously to me less accurate than my Springfield XD45 using same ammo.

[niemi24s]

How much up & down slop does the barrel have (in battery) when measured at the ejection port and the barrel's forced all the way up & down with a long wood dowel down the bore?

When in battery, is the barrel supported on the slide stop cross pin by its feet or by the link?

When you shot it, was the group shape sort of oval with the most spread vertical?

[Hill]

How much up & down slop does the barrel have (in battery) when measured at the ejection port and the barrel's forced all the way up & down with a long wood dowel down the bore?

When in battery, is the barrel supported on the slide stop cross pin by its feet or by the link?

When you shot it, was the group shape sort of oval with the most spread vertical?

The barrel is held up OK, but I see a burnished edge on the right leg of the barrel feet that makes me think that because of the barrel being wedged toward the right by the tip-of-foot contact the R/H burnished line is the only contact with the pin that the legs had.
I've taken about .005" off of both feet of the barrel legs now and there's no more contact at the bottom of the frame notch when I re'blued' it all with dye. So I think that that part of the issue is solved and it was no big deal once I knew it was happening. Without the force of firing I do have dye ruboff at both legs and I think on the pin too although it's kinda' hard to tell about the pin since it has to contact the frame on the way in and out.

The "group" was a ragged round - to tell the truth I couldn't have said that it had any up/down or right/left nature to it as it was too loose to learn from.

EGW sells a slidestop they call oversize and it seems to me that .200" + was mentioned in the description. Think I'll order one of those to see what effect taking away the .003" stop/hole fit has as a cheap and easy fix.

I'm not going to be able to fire the pistol at least for a day or two, except maybe out back of the house for function.