Ruger MKII Pistol Issues

Discussion in 'Technical Questions & Information' started by ucountmein, Sep 8, 2009.

  1. ucountmein

    ucountmein New Member

    May 26, 2009
    My Ruger MKII pistol has a problem with the bolt remaining open after the last shot is fired. If I push up on the Bolt Stop Thumpiece when an empty magazine is installed, the bolt will remain open. If I remove the magazine the bolt closes. If I remove the magazine and continue to push up on the thumbpiece it will remain open and the slightest movement of the gun will cause it to close. I have taken the gun apart (springs etc.) and cleaned every piece prior to assembling again.
    Is there something else I should be doing that will eliminate this problem aside from sending it back to Ruger. I have fired over 5,000 rounds and this is starting to occur now.
    Thanks in advance for any help with this issue.
  2. PPK 32

    PPK 32 Active Member

    Apr 15, 2008
    Frickin, Illinois
    Could be dead wrong here but its supposed to stay open. Tells ya there's no more to go. Only model that closes after the last shot is the Standard and maybe the Mk I. Unless you are referring to something else and I am missing it.

  3. Big ugly

    Big ugly New Member

    Feb 27, 2009
    Knoxville Tennessee
    Its dirty, Give it a good cleaning and then cycle some ammo through it. Should fix it.


    Jan 28, 2009
    The MkII has a last shot bolt hold open device. Removing the magazine will not allow the bolt to close, this must be done manually and the reason is somewhat simple. The button on the magazine when the magazine is empty moves the bolt release to lock it open, removing the magazine does not release the pressere already exerted on the release;but with the magazine removed and the bolt closed it will only lock back with upward pressure on the lever.

    The MkII is doing what is was designed to do, the MkI did not do this- hence MkII

    I can`t imagine than the wear with 5k of shooting would wear out this simple design, but things do occur.
    Remove the grip and check for wear on the bolt release stamping....either that or you have a MkI magazine and just forgot.
    Last edited: Sep 8, 2009
  5. Bindernut

    Bindernut Well-Known Member

    Oct 24, 2007
    ND, USA
    As I'm understanding it, it sounds like the bolt latch piece might be starting to get a little rounded off so that it releases too easily ("the slightest movement of the gun")

    It might also be that your mag spring is getting weak and isn't pushing the latch up into the notch on the bolt quite as far as it should. another reason it might disengage itself too easily. Or maybe just some missed crud in the notch on the bolt keeping it from engaging too.

    I'd try a fresh mag and if it still happens, I'd start looking at the condition of the latch. You might be able to redress a sharp edge onto the latch so it stays engaged better.

    I sure wouldn't think that the latch would be worn with only 5000 rounds through the gun, but the mag spring could be weak in that time.
    Last edited: Sep 8, 2009
  6. ucountmein

    ucountmein New Member

    May 26, 2009
    I want to thank all that replied to my plight. Bindernut might have hit it on the head with the rounding off of the bolt stop. I took the gun apart and noticed that the Bolt Stop was rounded. I also saw that the face of the Bolt itselt was marred at the point where the Bolt Stop made contact. Looking at the Bolt face when removed from the gun it would be the lower right corner of the Bolt face which was marred and rounded.
    In addition, I noticed that the long edge of the Bolt Stop (which is a stamped part) was not allowing the curved portion of the Bolt Stop to make contact high enough on the Bolt face. Being careful I used my dremel tool to reface the areas in question. The Bolt face was dressed flat, the Bolt Stop where the curved area that comes in contact with the Bolt Face was also dressed. The last area to correct was the flat edge of the Bolt Stop that came in contact with the Receiver Assembly. Here is where the most material was removed. Once the pistol was cleaned and assembled, it works as designed. Thanks again for your help.
    Last edited: Sep 15, 2009

    JUNKKING Well-Known Member

    Like BU said its dirty real dirty! Spray some break clean or break free whatever you use down into the bolt holder assembly and let it run out the bottom. Keep checking that assembly moving it by hand with no magazine in the gun until it moves freely and you don't feel any grit in there. Since I got the ultimate clip loader if I take my bride to the range with me. She will load all 8 magazines and just rip rounds off. She will shoot and shoot and can go through 1100 rounds faster than you can go through 200 from any other auto loader. Around 7 to 800 rounds into her fire fest this will begin to happen to all of my rugers.
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