Excessive MK-512 stoppages?

[98PK]

Have an old bull barrel Mk. II with probably 10k rounds fired, and lately it just has all kinds of stoppages; light strikes, failures to eject, stove pipes- just about has every kind of jam. I broke an extractor once and replaced it, installed a new recoil spring, and cleaned it out very thoroughly, but the pistol just keeps jamming up.

I noticed the bolt stop pin has significant wear on either side; flat-spotted on both sides where slide runs on it. When the pin has noticeable wear like this, will it cause a lot of jams or is it just today's ammunition, or both?

 

[Highstandardguy]

Did you clean your magazines thourghly? Do you have any "low mileage" magazines you can try.

Try some CCI Mini Mag ammo.

 

[98PK]

Magazines are okay. Shoot a lot of MiniMag and other ammunition of reputable U S A manufacture.

Has anyone here ever sent a 'Mainspring Housing Assembly Complete' to Prescott for replacement?

 

[SGW Gunsmith]

Magazines are okay. Shoot a lot of MiniMag and other ammunition of reputable U S A manufacture.

Has anyone here ever sent a 'Mainspring Housing Assembly Complete' to Prescott for replacement?

Are you thinking that the mainspring may be getting weak? The cleaning that you 've done, has that been recently? Before you send the mainspring housing assembly back to Ruger, you might consider getting a really good aftermarket extractor first. Contact this outfit : [email protected]. Ask about an extractor.

 

[98PK]

Cool, I may try one of those extractors at some point. Bolt stop pin is connected to the mainspring housing assembly in a way that I am not sure I want to mess with removing and reattaching (spring may be weak also?). I just sent the housing assembly to Ruger to replace. I'll see if that fixes things back to 100%.

I just wondered if someone had ever seen this pin get all worn and have sloppy action characteristics. Thanks for the posts.

 

[SGW Gunsmith]

Cool, I may try one of those extractors at some point. Bolt stop pin is connected to the mainspring housing assembly in a way that I am not sure I want to mess with removing and reattaching (spring may be weak also?). I just sent the housing assembly to Ruger to replace. I'll see if that fixes things back to 100%.

I just wondered if someone had ever seen this pin get all worn and have sloppy action characteristics. Thanks for the posts.

Yes, I have. I've seen some pretty horrendous things inflicted onto these Ruger Mark pistols, yet they do survive.



Why do the sides of the bolt stop pin wear like they do? The bolt is quite hard, the bolt stop pin, not so much. Seems the slot in the bolt gets a bit smaller toward the back end of the bolt and causes the metal on the sides of the bolt stop pin to wear away. The bolt stop pin as depicted above is out of a Ruger Mark II 5-½ inch barreled blue pistol. The owner fed his pistol a steady diet of CCI Stingers. The bolt stop pin is slightly bowed from the pounding it received from the bolt. What isn't apparent, is how the hole for the bolt stop pin in the upper surface of the receiver is noticeably egg-shaped from the battering it received. I replaced the bolt stop pin, no problem, but after showing my customer the end result of what his "SUPER" ammunition caused, he's now sworn off of Stingers.

 

[98PK]

That looks beat pretty bad.

 

[Precision32]

Check the fit of your extractor. The hook of the extractor needs to cam out at least 0.010" when a cartridge case is slipped up under the extractor hook. The case has to be held tightly in place on the bolt face until the back of the spent case hits the ejector to be kicked out of the ejection port.