Ruger MK 1 safety problem

[Rearsight44]

I have a problem with my Ruger MK 1, .22-caliber pistol. The pistol was manufactured in 1954 and purchased new by my father in 1955. I acquired the pistol after my father died 15 years ago.
If I cock the pistol (without it being loaded), then put the safety on, when I take the safety off about half the time the pistol will fire as if I pulled the trigger. Obviously this is a safety issue, no pun intended. I was wondering if anyone knows what I should look at or adjust to make this problem go away. I have deep cleaned the pistol by dismantling it and the problem is still there. Please let me know if you know anything about this problem. Thanks!

[Capt.Dunsel]

I have a problem with my Ruger MK 1, .22-caliber pistol. The pistol was manufactured in 1954 and purchased new by my father in 1955. I acquired the pistol after my father died 15 years ago.
If I cock the pistol (without it being loaded), then put the safety on, when I take the safety off about half the time the pistol will fire as if I pulled the trigger. Obviously this is a safety issue, no pun intended. I was wondering if anyone knows what I should look at or adjust to make this problem go away. I have deep cleaned the pistol by dismantling it and the problem is still there. Please let me know if you know anything about this problem. Thanks!

Replace the safety , sounds like the notch has worn down where it meets the sear . Since I would search Numrich for the part , Ruger might not have one for the older models such as yours.

[SkyHawk]

Ruger has had recalls for Mk IV series for exactly this reason. Note that the problem with the MkIV was partially blamed on the user. Of course that is a joke, but their explanation may give you some additional insight:

The issue is: In some cases, if the trigger is pulled while the safety lever is midway between the “safe” and “fire” positions and not full engaged in either, the pistol may or may not fire when the trigger is pulled.

If the gun doesn’t fire when the trigger is pulled, it may fire if the user then pushes the safety to the “fire” position without the trigger being activated.

In your case, the gun should be disassembled down to the last screw/spring/pin and inspected.

Here is a source for parts - but the safety is out of stock.

https://www.gunpartscorp.com/gun-manufacturer/ruger/auto-pistols-ruger/mki

You may have to check Gunbroker if you think the safety is what needs to be replaced. I don't see any there currently.

There is one for a target version on ebay right now, new old stock but not cheap

https://www.ebay.com/itm/Factory-Sturm-Ruger-Standard-Auto-MKI-Target-OEM-Internal-Safety-Catch-NOS-NEW/184065291482

The target version should be the same part but may have an extended knob for easier manipulation.

Before you go buying parts though, it needs to be examined in detail by someone who understands exactly how the parts interact so the problem can be identified.

[Rearsight44]

Thanks for the feedback!

[Fatcat]

This is one of better pictorial guides for complete disassembly/reassembly for the Ruger Mk pistols.

https://guntalk-online.com/service.html

[dfletcher]

Thanks for the feedback!

Buy extra safety detent and spring - at least two each.

[colt11]

It's an old gun, could it just be dirty? When's the last time you had the grips off to inspect underneath? Might try just a complete disassembly, cleaning, and reassembly, and then re-assess if you still have the problem. I've noticed the smaller parts get "sticky" from age due to the oils hardening.

[denpython]

Phone Ruger.
Shot in the dark but they might have one !

Glad I never use the safety on mine!

[Rearsight44]

Thanks for all your suggestions and links. I have completely dismantled the pistol (I didn't remove any pins to remove the smaller parts) and soaked it in acetone for an hour and scrubbed it inside and out with soft brushes, blew it out with compressed air, lubed it with gun oil and reassembled it. Now the safety works correctly about half the time. We are getting there...

[Sheldon]

All parts there? There is a tiny spring and detent pin that help hold the safety in position.

[beerman]

Send it back to Ruger. They have the best customer service in the business.