Ruger MKII 22 Automatic Pistol

[Whatnickname]

I’m relatively new to this forum but not new to the shooting sports. I was a competitor (Small bore rifles) for 16 years. I do quite a bit of my own gunsmithing. At the risk of offending some members, I have a particular fondness for the MKII 22 pistol...happen to believe that Ruger got it right when they came up with the MKII. I wish they had stopped there but things change and the evolution of Ruger firearms is no exception.

Seems like parts for the MKII were plentiful just yesterday and now they’re scarce. Like most of us that have been shooting for a lifetime, I’ve accumulated my share of parts and the MKII is no exception. I’ve had a stainless standard model upper in my bench drawer for several years and bought an almost complete lower on GB just recently...complete except for the mainspring assembly but, I had a spare one of those too so no problem. The issue for me was that I needed a bolt for my upper. Contacted Ruger CS and they advised that they had no MKII bolts but could fit a MKIII bolt to the pistol if I returned it to them. Saw an opportunity to purchase a MKIII bolt on e-bay for $40 and bought it. That bolt is brand-new. A comparison between this bolt and one from my other MKII show minimal differences. The most notable of which is that the lower edge on the bolt that engages the bolt hold-open piece is beveled at 45 degrees on the MKIII bolt whereas it’s at 90 degrees on the MKII bolt. Decided to give the MKIII bolt a try in my MKII pistol and low and behold it fit and the bolt locked back properly on an empty magazine...go figure. So my question is what changes do I need to make on the MKIII bolt to get it to function correctly in my MKII pistol?

 

[NikA]

Sounds to me like you've function checked it absent shooting it. As far as I know, the main functional difference between a Mk III and II bolt is the presence of the slot for the LCI, which shouldn't affect function.

Time for a shooting test, I'd say. When Ruger says they'll 'fit' something, they most likely mean 'assemble with off the shelf parts and function check," which you already appear to have done.

 

[Whatnickname]

Thank you. Headed to the range this weekend.

 

[Dan in MI]

I've swapped an awful lot of bolts from early Std/MK-I through Mk-III with no issues.

 

[Whatnickname]

I've swapped an awful lot of bolts from early Std/MK-I through Mk-III with no issues.

Good to know. I’ve changed yet another bolt (MKIV) out in two of my MKIIs. Both function perfectly. My feeling is that either the MKIII or a MKIV bolt will run just fine based on the way they function. Wonder why Ruger insisted that I return the pistol to them to have the bolt “fitted”… no fitting necessary from where I sit.

 

[TestEngineer]

The "fitting" is probably just swapping out the bolt stop and function testing. As you noted, the angle on the bolt is different. This will beat up the mk2 stop over time. You really should replace it with one made for a mk3.

 

[Whatnickname]

The "fitting" is probably just swapping out the bolt stop and function testing. As you noted, the angle on the bolt is different. This will beat up the mk2 stop over time. You really should replace it with one made for a mk3.

Hadn’t thought about that. Just went on line and ordered a MKIII bolt stop. Inexpensive part and worth not having a headache. Thank you!

 

[Danny]

I’m relatively new to this forum but not new to the shooting sports. I was a competitor (Small bore rifles) for 16 years. I do quite a bit of my own gunsmithing. At the risk of offending some members, I have a particular fondness for the MKII 22 pistol...happen to believe that Ruger got it right when they came up with the MKII. I wish they had stopped there but things change and the evolution of Ruger firearms is no exception.

Seems like parts for the MKII were plentiful just yesterday and now they’re scarce. Like most of us that have been shooting for a lifetime, I’ve accumulated my share of parts and the MKII is no exception. I’ve had a stainless standard model upper in my bench drawer for several years and bought an almost complete lower on GB just recently...complete except for the mainspring assembly but, I had a spare one of those too so no problem. The issue for me was that I needed a bolt for my upper. Contacted Ruger CS and they advised that they had no MKII bolts but could fit a MKIII bolt to the pistol if I returned it to them. Saw an opportunity to purchase a MKIII bolt on e-bay for $40 and bought it. That bolt is brand-new. A comparison between this bolt and one from my other MKII show minimal differences. The most notable of which is that the lower edge on the bolt that engages the bolt hold-open piece is beveled at 45 degrees on the MKIII bolt whereas it’s at 90 degrees on the MKII bolt. Decided to give the MKIII bolt a try in my MKII pistol and low and behold it fit and the bolt locked back properly on an empty magazine...go figure. So my question is what changes do I need to make on the MKIII bolt to get it to function correctly in my MKII pistol?

The MKI was a good start. Ruger got it correct when they made the MKII. The MKIII was a train wreck. The MKIV is a solution to a problem that never existed. I might buy a nice MKI, but much prefer a MKII. Would never consider a MKIII or MKIV. I don't really care for a lot of things that Ruger started doing after "The Old Man" departed. Ruger had kind of a unique niche during his stewardship. The new guys took what was unique, then threw it out, trying to be like "the other guys", or to be "everything to everyone", then ruined it all.

Danny

 

[Mobuck]

After buying a couple of MK3 22/45 pistols, I consider the MK3 a 'skeleton' recipient for MK2 'updates'. Nothing wrong with the basic assembly, just needs addition of good parts.
When a basic 22 pistol can produce 3-4" groups @ 100 yards consistently using less than competition grade ammo and do so across multiple specimens, the mechanics are good enough. Fortunately, the MK and 22/45 series allow the substitution/addition of parts that make them 'user friendly'.

 

[AzShooter1]

Ruger always wants you to send the gun in "for fitting". They also say parts are not interchangeable, good example is the bolt. I needed one for my Mark III and CS told me it had to be new and would cost $75. I ordered one from E-Bay for $40 and it works perfectly.

They are trying to cover their ass against lawsuits, and make a little profit.

 

[Highstandardguy]

The "fitting" is probably just swapping out the bolt stop and function testing. As you noted, the angle on the bolt is different. This will beat up the mk2 stop over time. You really should replace it with one made for a mk3.

+1, When Ruger replaces a MKII bolt they also replace the bolt stop assembly as well with a MKIII version. When I have one replaced, I just send the bolt and indicate the serial number of the pistol it came off of. Never had a problem yet. They send me a bolt and the correct bolt stop assembly.

 

[fallsinhole]

Hadn’t thought about that. Just went on line and ordered a MKIII bolt stop. Inexpensive part and worth not having a headache. Thank you!

Want to make sure there is a small gap between the bolt ears and the back of the receiver with the bolt in battery, if no gap the bolt ears will get beat up as well as the rear of the receiver!!

 

[Highstandardguy]

Never thought to check that and never had an issue, but I'll check it from now on. Thanks for the heads up.