1. This site uses cookies. By continuing to use this site, you are agreeing to our use of cookies. Learn More.

Square slides?

Discussion in 'Handguns: Autoloaders' started by chris in va, Nov 12, 2012.

  1. chris in va

    chris in va Well-Known Member

    Glock seems to be one of the pioneering designers of the square slide. Just curious why he came up with the design when most other semiauto's at time of conception had rounded tops. Other manufacturers have copied the profile...Springfield etc.
  2. Jim K

    Jim K Well-Known Member

    Partly just style, but also a slide for a given caliber has to have a given weight (mass) if it is not to batter itself and the frame. One way to add mass to any rounded object without adding size is to fill in the corners, and the square slide does that.

  3. Greg528iT

    Greg528iT Well-Known Member

    Designing for cheap manufacturing. Much cheaper to mill cut a square than a contoured surface.
  4. Shadow 7D

    Shadow 7D Well-Known Member

    Glock wasn't all that innovative on the GUN side
    rather on the production side.

    There is a major trade off, ever see a glock CC holster, square doesn't hide that well.
    BUT glocks aren't really sold to that crowd anyways.
  5. dogtown tom

    dogtown tom Well-Known Member

    When was the last time you read the ATF's "Factoring Criteria for Weapons"?:scrutiny:

    Glock is over 500,000 firearms behind.....they don't really need more models to slow down production.
  6. chris in va

    chris in va Well-Known Member

    Interesting point about milling.
  7. jon86

    jon86 Well-Known Member

    Interesting thread. I've always thought the glock would conceal much better with a rounded slide.
  8. The Lone Haranguer

    The Lone Haranguer Well-Known Member

    SIG-Sauer actually pioneered the squared chamber shoulder lockup with the P220 in the 1970s, not Glock. This is easier to machine and fit than conventional locking lugs.
  9. CZ57

    CZ57 member

    The Croations did similar with the HS-2000/XD but the XDm has a different profile. ;)
  10. 1911Tuner

    1911Tuner Moderator Emeritus


    Rounded slides require radial locking lugs. Radial lugs engage horizontally between 10 and 2...which doesn't provide a lot of surface area to keep the slide and barrel from separating unless multiple lugs are used. The squared slide and single massive lug equals or exceeds the locking area.

    In all tilt-barrel designs, the barrel lugs engage vertically, but they lock horizontally in opposition under shearing forces.

    Note that the rounded slide/radial lug arrangement also has a chamber shoulder lockup. It's the first lug wall...the one without a space behind it. Being more supported, and having maximum vertical engagement, it's the strongest one of the three...while the other tilt-barrel Browning designs lose a little vertical depth in the slide with each progressive lug. i.e. The #2 lug vertically engages with about 90% of the depth of the first lug. #3 loses an additional 10%. (These figures are approximate.)

    It's also simpler...read cheaper/faster...to manufacture when there's only one lug to worry about meeting spec.
  11. 1911Tuner

    1911Tuner Moderator Emeritus

    Let's keep this one purely technical.

  12. beatledog7

    beatledog7 Well-Known Member

    If only that were possible. If the word "Glock" appears, the thread goes Fanboy vs Basher in a heartbeat.
  13. ku4hx

    ku4hx Well-Known Member

    Just mill the square barstock, round a corner or two and skip the gross re-contouring. Lowered the production cost and created a "new" look. And the rest, as they say, is history.
  14. 1911Tuner

    1911Tuner Moderator Emeritus

    Oh, most assuredly possible. Go and look.

    Let's continue.

    It would...a little...but rounding the slide would necessarily reduce the width of the single locking lug...which would weaken the breech. You can have a round-topped slide with multiple radial lugs, or a square slide with a single massive lug. Pick one.
  15. Ash

    Ash Well-Known Member

    SIG did so not to reduce milling in the 220, true, but it is more of a product of the slide construction. The slide was stamped (though folded is the current description), and it is just plain impractical to round a slide and mill lugs when your goal is to stamp its shape. The question is did the single large lug lead to the folded slide or the folded slide necessitated the use of a square lug? Either way, Glock copied it 7 years after SIG introduced it and so it is hardly original on the Glock - indeed nothing is original on the Glock - all features were pioneered by other companies in other pistols. Of course, Glock combined the features into a single pistol, and so the Glock was the first, you could argue, to do it all at the same time. It is, in short, an example of the best that Browning, SIG, Hk, Lee, and others created over more than 100 years.

    The squared-slide profile is popular, but there are many designs that do not use it. They are all solid, rugged, and reliable.
  16. Stringfellow

    Stringfellow Well-Known Member

    An observation from someone working in a different industry... Glock is the Apple of the firearms world: less about innovating anything, but more about putting it all together and marketing it well. The result is the same too--massive overall success, massive profitability (compared to other innovators), industry dominance, and a fervent group of followers who are, well, fervent nonetheless.
  17. The Lone Haranguer

    The Lone Haranguer Well-Known Member

    This has proven very popular, with many, if not most, newer guns using it.
  18. 1911Tuner

    1911Tuner Moderator Emeritus

    Yep. A lot easier and simpler to attain the same breech strength. It's a little tricky to get three lugs to bear the brunt of the recoil forces equally when three barrel lugs have to meet three slide lugs. There are six linear distances that have to coincide instead of two.

    And this is also where the single massive lug has an advantage over three radial lugs in terms of strength...and where the Glock fans can reasonably argue that their choice is superior to the 1911.

    If the three radial lugs aren't equalized...and few mass-produced 1911s meet that criteria...then the breech strength is not only lessened...longevity is also compromised.

    Even if the three are equalized, and have maximum vertical engagement, the load is concentrated on a narrower area...between 10 and 2...while the single square lug's load is dispersed over the entire width of the lug. Advantage: Glock

    Finally...from a manufacturing standpoint...it's simpler, faster, and cheaper to machine squares than contours.

    I still prefer the 1911 because of the trigger and because I can't wrap my hand around a Glock to save me outta torment, but that's a matter of personal preference and thus has no place in a technical discussion.
  19. RON in PA

    RON in PA Well-Known Member

    Wasn't this first done by Petter with a pistol he designed for the French in the 1930s?
  20. hentown

    hentown Well-Known Member

    And now for the real answer. The squareness of the Glock slide is the result of the true genius of the Austrian engineers who designed the pistol. A square slide is much easier to grip with the weak hand for cycling the slide.

    Whoever posted that the Glocks are not sold to the CCW "crowd" is just babbling incoherently. ;)

Share This Page