1911 slide fit


PDA






dashootist
July 17, 2012, 09:01 AM
Hi. What is considered to be tight slide fit on a 1911?

I am looking at a Caspian, and when slide is locked, it is very tight--no free play at all. I took it apart, and I just happend to put the gun all back together with everything but the recoil spring. Without the recoil spring, there is about .002" free play in the side-to-side between frame and slide. I don't know if this is proper way to determine slide tightness. Is this normal for a custom gun. I thoght this is kind'a loose. But this is also the first time I felt a 1911 this way without the recoil spring.

If you enjoyed reading about "1911 slide fit" here in TheHighRoad.org archive, you'll LOVE our community. Come join TheHighRoad.org today for the full version!
skipsan
July 17, 2012, 10:36 AM
Don't have my reference in front of me, but my recollection is that a field-grade 1911 might have 3-5 mils of lateral and vertical slide/frame running clearance and that would be considered OK. A fitted/match grade 1911 might have 1 mil running clearance. If you can get hold of Kuhnhausen's VII, the issue is discussed at some length and the precise numbers (as far as he's concerned) are presented.

9mmepiphany
July 17, 2012, 10:46 AM
Interesting, who built your 1911?

I just happened to have my 1911 build-up on the desk next to me and gave it a shake. My frame and slide fit don't exhibit any looseness increase without the barrel, link, bushing, recoil assembly and slide stop removed...as long as the rear of the slide and frame are aligned. Also the rails have been completely degreased.

It almost sounds like who ever fitted your slide/frame used the lock-up pressure to take out the slack.

Skylerbone
July 17, 2012, 11:54 AM
Measuring would provide accurate hard numbers but if expectations were not discussed before work commenced you would be hard pressed to find fault with the builder unless there is an excessive amount of slop. Each smith will build to his own standard, ideology and method which makes choosing one whose builds match your wants imperative.

A hard fit barrel can eliminate vertical play but lateral movement may still be evident. Break out the calipers and check several areas then discuss the facts with the smith.

918v
July 17, 2012, 09:11 PM
And how did you come up with .002"? That would be almost imperceptible.

crossrhodes
July 18, 2012, 09:23 AM
How did you measure? is it .001 per side?

918v
July 18, 2012, 11:35 AM
I typically see near zero horizontal clearance in the back at the beavertail and .010" or more up front by the slide stop pin. You can see it by looking at the dust covers and moving the slide side to side.

If his gun has .002" all around, he has a gem.

Vern Humphrey
July 18, 2012, 03:39 PM
Let me point out, the important fit on the M1911 is the barrel lockup. The sights are on the slide, and if the barrel locks up the same way, every time, you will have an accurate pistol, even if there is some play between slide and frame.

The real answer to your question is, "Ask the gun." Take it out and shoot it. If it shoots accurately, its an accurate gun, regardless of how the frame fits the slide.

dashootist
July 18, 2012, 10:53 PM
In my original post, I meant both the barrel and recoil spring were taken out when I got .002" measurement. Yes, .001" per side. I used a dial caliper by Brownells.

With everything parts back in the gun, it's real tight. No measurement play at all.

9mmepiphany
July 18, 2012, 11:50 PM
Is this normal for a custom gun.
Who built it for you?

How tight did you ask for the slide and frame to be fitted?

1911 guy
July 19, 2012, 02:37 AM
Frame to slide fit is over-rated. It is the least important area for accuracy and reliability, but it's cheap to do and sells guns to the uninformed. Bushing to frame, bushing to barrel, barrel locking lugs to lugs in the slide, even the correct relationship between the slide stop pin and barrel link have more to do with proper functioning and accuracy than simple frame to slide fit.

In short, as long as the guns runs, don't worry about it. If it doesn't run, look elsewhere for your problem.

918v
July 19, 2012, 10:19 AM
In my original post, I meant both the barrel and recoil spring were taken out when I got .002" measurement. Yes, .001" per side. I used a dial caliper by Brownells.

But where? In the front by the dust cover or in the back by the hammer?

Skylerbone
July 19, 2012, 11:22 AM
it's cheap to do and sells guns to the uninformed.

Cheap? Sure. A TIG welding set-up, a mill, a Kurt vise, some files and lapping compound plus time. Cheap yes, easy no. Uninformed? If you're describing the typical end-user who casually shoots a few hundred rounds over a decade then I might agree it's a non-issue. I cannot deduce all such people are uninformed, only suspect as much. If we are discussing those who shoot for accuracy I could not disagree enough.

There are a number of dimensions that determine a 1911's accuracy. Some account for a significant percentage of the equation but the formula cannot be complete without each step being addressed. It is always a theoretical perfect and only a few will ever pursue it in earnest.

918v
July 19, 2012, 07:23 PM
Frame to slide fit is over-rated. It is the least important area for accuracy and reliability, but it's cheap to do and sells guns to the uninformed. Bushing to frame, bushing to barrel, barrel locking lugs to lugs in the slide, even the correct relationship between the slide stop pin and barrel link have more to do with proper functioning and accuracy than simple frame to slide fit.

You can have the best relationship between the parts you mentioned, but if the slide isn't tight on the frame, those parts will wear loose in a couple thousand rounds. You can build it right the first time, or you can rebuild it once a year or not if you don't care about this sort of thing.

Springfield Armory Custom guns are built so tight, air cannot escape, but they will also shoot like the day they were new after 50k rounds.

If you enjoyed reading about "1911 slide fit" here in TheHighRoad.org archive, you'll LOVE our community. Come join TheHighRoad.org today for the full version!