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Mr bullseye
please explain to me more about this pin upgrade for the 22/45 MkII
http://www.guntalk-online.com/images/2007_2245m3_2.JPG

I just picked up a bull barrel 22/45 MkII for the fun of it at $250. It is like new.

Also will the MkII 22/45 and MkII regular uppers and lowers interchange?

The pin was changed last year to prevent frame damage from hammer pin walking. Even with the locking springs properly placed some hammer pins walked to the right and caused the frame to tear out in the pin boss area. Here's an example of a walked hammer pivot pin.



And inside the frame looks like this-



If you don't have the new pivot pin with the head on it, you can get one by calling Ruger customer service.

As far as 22/45 and regular uppers interchanging, some will and some won't. Generally the 22/45 receivers do not swap onto a regular metal frame as the receivers are peened on the underside, near the front lug, to keep the receiver tight on the frame.



This peen prevents the receiver from fitting on the front lug of a regular frame. The best I can say is try swapping them. Sometimes they do like this one did-



The receiver undersides (mkII and mkIII) have identical dimensions.



Hope this helps.

R,
Bullseye

I called Ruger parts about the pin. man said it is for MKIII only so i didn't need it.

That's funny! All this time I didn't notice that you had asked about a Mark II. I must have skipped over that part and thought you were asking about a Mark III 22/45. The frame on a Mark II 22/45 is much thicker in the pin boss area and therefore the Mark II does not need this style of pin. If the pin travels a little in the 22/45 Mark II frame, there's plenty of material to support the hammer, and the frame will not tear out like a Mark III 22/45 frame does.

Here's why you don't need that pin on a Mark II 22/45.



The two frames are shown and the arrows demonstrate the relative frame thickness at the pin boss area. Both hammer pivot pins are slightly recessed in their respective frames. That doesn't leave much frame material were the hammer pivot pin resides in a Mark III frame. But when you consider that a Mark II 22/45 frame is considerably wider than the Mark III 22/45 frame there's plenty of frame support in the Mark II.



Because the newer Mark III 22/45 frame was significantly thinner and the hammer pivot pin was moving, the frames were getting torn out on the left side due to a combination of pin walking and mainspring tension.



My apologies for not answering your first question properly. I should have noticed that you were inquiring about a 22/45 Mark II frame and not a Mark III. Which also explains why I showed you a Mark III receiver on top of a Mark II 22/45 frame. However, the same reasoning applies between a Mark II 22/45 receiver and a regular Mark II/III (metal) frame.

Hope this helps.

R,
Bullseye

Just read this thread and took a good look at my Mark III 22/45 - I need to get the new pin. Thanks Bullseye! Love this forum - Great info.

Make sure that you don't already have the new style pin. If your pistol was made after June 2007 then you probably do have the new style hammer pin. Look at this picture.



If your hammer pin sticks out of the frame on the left side, then you have the new type pin.

If it doesn't then call Ruger and they'll send you a new hammer pin. If your frame has signs of tear out the new style pin will prevent having to replace the frame.

R,
Bullseye

Thanks for the additional reminder - My Mark III 22/45 has the old style pin. Serial number indicates circa 2005 as manufacture date. Hope other 22/45 owners see this thread...

OpsMgr wrote:Thanks for the additional reminder - My Mark III 22/45 has the old style pin. Serial number indicates circa 2005 as manufacture date. Hope other 22/45 owners see this thread...

It's pne of those things, the old style pin may never cause a problem and then it may. Might better change it before it can cause a problem. Just like a spare tire, you may never nedd it and you may also.