m40a1 slide catch issues

Discussion in 'Maintenance / Tweaks / Technical Difficulties / So' started by mr. ford, Dec 24, 2007.

  1. mr. ford

    mr. ford Guest

    so a little bit over a week ago i decided (after classes during finals week) to go unload some rounds at a local indoor range (bit winterish outside) through my 40 cal.
    i unloaded my first magazine and the slide did not catch and lock in the open position.
    i found this odd, so i took my other magazine (the set with n.i.b. purchase), loaded it, fired it empty with the same result-- an empty magazine and a cocked trigger.

    i've only put 100 rounds through this gun since purchased new (haven't yet had time!), haven't fully stripped it, just quick removal of the slide to do a spot check here and there.

    the catch lever performs how it should when manually engaged.

    any ideas before i call SAI?

    thanks, j. ford
  2. Syntax360

    Syntax360 Premium Member

    The problem is most likely the magazines. Where did you get the pistol from? Mine came from Davidson's Gallery of Guns and I had the exact same problem. I would advise you to call SAI and explain the problem - they will likely get two new mags on their way to you and give you a FedEX # to send back the old.

    The problem seems to be that at least one run of pistols was sold using 10 round springs in the 15 round mags. You often see the same problem in a pistol using a magazine with a fatigued spring... There have been a few reports of this, all on pistols originating from Davidson's, I believe...

  3. heavymetalmachine

    heavymetalmachine New Member

    Mine came from CDNN..

    2 came with the pistol

    2 I got for extras

    1 had a short spring..

    It worked well at first but after I left them loaded for a short time the springs broke in. Now the short spring runs all the rounds out fine but it never locks the slide back..

    Theres lots more good info here viewtopic.php?f=4&t=4309

    I still need to get mine fixed.. I'm just soooo lazy sometimes..
  4. mr. ford

    mr. ford Guest


    yea this sounds quite plausible for my situation.
    i'm going to call SAI later today, during business hours.

    i'd imagine and hope that SAI would perform how you, syntax has described!
  5. Texasman71

    Texasman71 Guest

    I had the same issue. With a M9 A1. What I did to remedy the problem.. Slightly bend the slide catch lever up at it's rear contact point. Where it makes contact to lock in place.

    And I do mean slightly, Close tolerances here. A set of needle nose pliers is all ya need. Or a new set of mags like others have said. So far I still have the old mags and they function well. After 1500 rounds.

    Also I should mention looking down the poleymar frame at eye level from the rear the catch lever is in line after the bend procedure. Meaning the rear of the slide catch is level with the plastic part of the gun. Looking down the frame and rail slide. You can only see this with the slide / barrel off. No mag installed basically your tweaking the rear part of the slide lever to be in line with the pastic part of the frame.

    And before someone flames me this is tested and true it does fix this issue.

    This fix enables you to use your old magazines, with out interfering using the new spring magazines. As well...

    Hope this helps :mrgreen: