Ruger MKI not cocking?

[shc4life580]

Hi, I'm new to the forum, but after reading through several posts, I figure this has to be the place to get an answer.
I've got a Ruger MKI thats acting funny. After I chamber a round and fire, it won't cock the hammer back after ejecting the casing and chambering the next round, I have to manually pull back on the bolt. This is the funny part: pull back on the bolt slow and let it close slow, hammer cocks; pull back on the bolt fast and let it close slow, hammer cocks; pull back slow and let it slam forward, hammer doesn't cock; pull back fast and let it close fast (as if it's been shot), hammer doesn't cock.

I've replaced the trigger spring, sear spring, and recoil assembly with factory parts from Ruger. I replaced the sear with a Volquartsen, since Ruger won't ship that part out. The gun has been detail stripped and cleaned, and put back together (properly, yes, even the sear spring is in the right direction, made sure to do that just right). I read in a post on these forums that if you pull the pull slowly and it cocks that it may need a new sear, seeing as I've already replaced that, could it be a worn hammer? Both the sear and hammer have what look to be either file marks or rubbing marks. Don't have much history on the gun, so I don't know what modifications they may have tried to make. I only paid $70 for it, at this point i've put more into new magazines, springs, grips etc. Any help would be greatly appreciated, I'm eager to start putting rounds through my new toy.

 

[rugerguy]

everytime the bolt goes "back", the hammer has to cock, its not "staying" cocked ( it's following down...) sear notch in the hammer is my guess from what you have said, but other things can be going on ,the sear itself, the trigger bar, etc.............when it does it when firing, it can also even be the ammo.......sear, its angle and the notch in the hammer are critical, as well as the spring tension and the trigger bar,all should be looked at.

 

[Jeepnik]

Boy I'm reaching back over thirty years, but I once had my MKI go full auto. I put in another mag, and when I chambered the first round it emptied the magazine again. Turned out to be a busted spring, but darned if I can remember which one.

 

[96/44]

I'm assuming you've already thoroughly cleaned and lubed the gun? It sounds to me like the sear is worn out, it has happened to me on both my MKI, and MKII. disassemble the pistol, and look very closely at the engagement surface of the sear. It needs to be perfectly square, if it is starting to round the edge off, it can't catch the hammer.
EDIT: Duh, maybe I should have read your post a bit closer, I see that you've already replaced the sear. You're probably on the right track with the hammer, good luck!

 

[nvbirdman]

Since it has a new sear, I'm sure the problem is with the hammer. Ruger most likely won't sell you a hammer either, so you will probably have to send the gun back to the factory, but before you do, remove the Volquartsen sear or Ruger will replace it with a factory sear.

 

[shc4life580]

I replaced the sear, my next guess was the hammer, mainly because just about everything else has been replaced, the only other option was the disconnector and i observed the action with the barreled receiver off and it disengaged the sear and hammer fine, as you said rugerguy the problems seems to be the hammer not staying cocked and mine did show signs of filing/wear. Thanks everybody, these are the best answers I've gotten so far. I've already bookmarked this forum.

 

[rugerguy]

If you "need" a hammer, let me know, I will try and come up with one for you,but yours should be able to be "trued up" ( recut) hopefully they did NOT remove material from the 'face' ( front) on the upper portion,,,,then you'd have to remove some from the 'lower' frnot so there is the 'step' for the sear to catch.................there is quite a bit of "play" with the sear to move back and forth ( in and out...)and the spring just needs to be strong ewnough to keep it "engaged" and NOT bounce or slip out...same goes for the "fit" as said above, it has to be "sharp" ( even) and NOT rounded off............

 

[shc4life580]

Rugerguy, thanks, I managed to find a guy on another forum that had the VQ target hammer for $25 shipped, which is awesome seeing as on average its $45 plus shipping at all the online sites. I figured I'd give it a try since I already installed the VQ sear. I'll keep you posted though, as right now VQ is 50/50 for me, first purchase was the extended mag release, it ended up being a $15 waste, refused to fit after an hour of filing, and when I finally got it in it would wedge the magazine towards the front of the magazine well so that it would only go about halfway in. Luckily the sear was a true drop in part.