Impact of slide to frame fit on accuracy?

Discussion in 'General 1911 talk' started by B81, Oct 30, 2020.

  1. B81

    B81 Well-Known Member

    Aug 12, 2018
    How significant is the slide to frame fit on the accuracy of a 1911? I've read a lot of conflicting information about this. Some argue that, since the sights are on the slide, all that matters is that the barrel and slide have consistent lockup, and that slide to frame fit is purely aesthetic (i.e. has more to fit and feel than performance and function). Others argue that slide to frame fit does indeed matter, as it is essential to achieving consistent lockup.

    So, what says 1911Addicts? We have some top notch smiths here, as well as some with extensive experience shooting a wide variety of 1911's. I'm curious to know what you guys think. Has anyone done any kind of meaningful side-by-side comparisons?
    Greenrunner and Brennerman like this.
  2. Integrity Arms

    Integrity Arms 1911 Pistol Smith

    Mar 20, 2017
    Watch this and tell me? lol I personally think slide to frame fit has 0 to do with accuracy... It's hard even at this speed to tell if the barrel even starts to link down before the bullet exits. But, I do believe by the time that happens and the slide starts to move the bullet is long gone.

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  3. wrmiller

    wrmiller The Tinker

    Oct 29, 2016
    When I worked for Bob, I met and talked to a few well known bullseye smiths and shooters in the LA area. The general consensus was that tight wasn't as important as positional repeatability. In other words, if all critical parts go to the exact same spot every time the pistol goes into battery, the pistol will shoot as well as the barrel, ammo, and shooter allow it to. In their opinions the barrel, slide, barrel bushing, and slide stop pin were the critical components to overall accuracy. Trigger setup is important too, but this is more of a pistol control issue for the shooter than controlling the accuracy of the pistol itself.

    Slide to frame fit helped more with smooth and reliable/repeatable functioning. Too loose, or too tight, and it could cause functioning issues. The critical component of slide to frame fit (as I was told/taught) was the vertical play. As long as the vertical play could be taken out by the barrel's lower lugs riding up on top of the slide stop pin and forcing the barrel and slide up against the lower registration surface of the frame's rails, everything was good.

    I went to LA once to watch a customer of ours shoot. He was shooting a basic 45 that had a Bomar (?) rail mounted on top with integral sights. This pistol was loose as a goose by today's standards, but I watched him put three shots into one ragged hole, at 25 yds, standing, one-handed.

    This is just what I've heard/learned. YMMV... :)
  4. Dallas Knight

    Dallas Knight Max Otto von Stierlitz

    Jun 22, 2015
    Great little video.

    Goes a long way in explaining why I keep my weapon light lens covered with plastic electrical tape while practicing at the range (much less cleanup)!
    Integrity Arms likes this.
  5. NPV

    NPV Well-Known Member

    Nov 15, 2017
    Chapstick works better, no sticky residue.

    To answer the OP based on what I’ve been told and discussed 5%.
  6. fallenangelhim

    fallenangelhim chicken wings

    Jan 18, 2018
    @Integrity Arms can you talk about the issue with my Colt Commander barrel? Remember we both had horrendous accuracy and lots of slop on hood and lugs.
    Integrity Arms likes this.
  7. Integrity Arms

    Integrity Arms 1911 Pistol Smith

    Mar 20, 2017
    Well you had no lower lug contact between the slide stop pin and lower lugs, due to the fact that the lower lugs had been over cut to provide upper lug engagement. Also there was little to no engagement at the slide stop or the upper lugs. So when the barrel was at rest there was movement everywhere because in essence you had no lockup anywhere.
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  8. Cop_Out

    Cop_Out Pearl Pimp Supporting Addict

    Feb 3, 2017
    Great vid, Steve. Thanks or posting.
    Integrity Arms likes this.
  9. Integrity Arms

    Integrity Arms 1911 Pistol Smith

    Mar 20, 2017
    I guess I would have to concede that slide to frame fit, could play into accuracy some if it were to cross the line of being grossly loose.. But, imo it would have to really be a mess. It is shocking sometimes to feel how loose a gun actually feels when it's only a .002 discrepancy in tolerances. But, the Colt I just ransom rested had a little horizontal and vertical movement, and still shot a 1" group at 25 yards in 8 shots. Well 1.133 And to get an idea how much .002 play in a slide to frame is, a human hair is .003 a piece of paper is .004-.005

    Last edited: Oct 30, 2020
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  10. simonp

    simonp Well-Known Member

    May 27, 2016
    I have heard and read from multiple sources / smiths that the barrel lock up is what matters, the slide to frame fit doesnt. The nice sweet slide to frame fit is something that folks like and perceive as a necessary quality on an expensive semi or custom gun. In all the years of having guns built I have never had anyone tell me I need it or try to upsell me on the slide to frame fit except once - a smith I sent a bone stock, BNIB colt to told me he could not work on the gun without welding up the frame or replacing the slide with a new one, too far out of spec. I had him ship me the gun back and thanked him for his time.
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