I need some help with a slamfire problem! I’ve had this problem for several years. (The firing pin is not stuck causing this problem, I think it‘s more of a hammer/sear problem) If you pull the bolt back and return the bolt forward by hand it doesn’t fire. If you pull the bolt back and release your hold on the bolt and let spring pressure return the bolt it will fire. If you return the bolt by hand, then hit the back of the bolt with a hard rubber hammer it will fire. If you return the bolt by hand, put it on safe, pull the trigger then let off the trigger and take off the safety it doesn’t fire. I had a local gunsmith work on it a couple of times a few years ago, but he wasn’t able to fix it. Now I’ve dug it out of the gun safe to work on it, again…. I installed a Wolf spring kit and it still does it. I thought maybe the mainspring plunger is binding up, so I used a bronze bore brush to scrub the mainspring passage and polished up the plunger surface with the drill press and stones. That didn’t fix it. The Wolf trigger spring is stronger than what was in it. I had high hopes that would fix the problem, but it didn’t. With the gun apart, it feels like there is positive engagement of the hammer and sear, but it must not be enough. I can not see any of the trigger parts binding that would hold the sear forward. I’m leaning toward getting a new hammer and or sear. Any suggestions on what brand and where to get it/them? Thanks in advance for any help you can give.

Well, figuring I didn’t have much to loose at this point, I filed/honed the sear to hammer surface some. It helped, as it would no longer fire when the bolt was released or moderate taps with the hammer. A hard rap with the hammer would still make it go off. Tried a few rounds through it, and it would still occasionally slam fire. Not as often as before, but it was still doing it. Thanks to Georgezilla from RimfireCentral.com for pointing out the trigger pre-travel adjustment screw. I had not noticed this screw/adjustment (and that’s the reason I’m not afraid to ask for help ). I turned the screw in one turn and hit the hammer with a stone once more. I have high hopes that’s fixed it. It doesn’t fire when the hammer is released or from a pretty hard hit from the hammer. I won’t be able to test fire until tomorrow. Wish me luck!

I shot around fifty to sixty rounds today at the range and did not have one slam fire. Makes me feel good knowing I fixed my pistol when the local gunsmith couldn’t. But I probably worked on it six hours more than he did. Yeah, I spent a long time honing on the hammer….. But it works again!

http://www.mkiii.org is always a good source for MarkII/III information.

Thanks for the link a/c guy. I hadn't heard of that site. My MKII is working again, but I'll put that site in my favorites just in case I have more MKII questions in the future