Ruger Mk II Issue(s)

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1chessiefan

Bearcat
Joined
Jun 3, 2022
Messages
15
Location
Ohio
Friends,
I had a bull barrel and a picatinny rail installed and an action job done on a Mk II. The pistol was blued. I shot it several times with no issues. Last weekend I shot it and when I finished I put a spent casing in the chamber so I could dry fire it to release spring tension. I went to the range a day or so later and could not muscle the bolt back. I took it home and was able to get the bolt to go back with a 22 cleaning rod and a rubber mallet. I had to drive the mainspring pin out with a wooden dowel and the mallet. I now cannot get the pistol reassembled. The ms pin does not want to go in all the way. I have tried using a different ms assembly and bolt assembly and obtain the same result. I have tried slightly adjusting the frame receiver alignment but it makes no difference. Once or twice I was able to fully insert the ms pin when the bolt was not in the receiver but now I am unable to do even that. Any thoughts/suggestions/guidance would be appreciated. Thank you!

1chessiefan
 
Last edited:

Johnnu2

Hunter
Joined
Jun 26, 2003
Messages
2,844
Location
NYS
I would recommend that you "google" Ruger Main Spring Pin.
See if any assembly instructions pop up... :)

J
 

Johnnu2

Hunter
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Messages
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I hope he followed my lead because that search would take him to a very detailed assembly guide from "another" Ruger forum that I didn't want to mention/advertized on our Forum. The detail would certainly get him 'fixed' if he took the lead I gave.

J.
 

1chessiefan

Bearcat
Joined
Jun 3, 2022
Messages
15
Location
Ohio
Dear and Johnnu2,
I have fiddled with it some and have not got it back together. I did a search as Johnnu2 suggested and got some ideas. It will be a little while before I can spend some more time on it. I will report back. Thank you for your assistance.

1chessiefan
 

Xrayist

Single-Sixer
Joined
Nov 9, 2007
Messages
240
Location
Fort Collins, CO
1chessiefan: Hope you get it back together. Please remember a spring weakens by loading/unloading tension. Keeping one compressed causes mo more wear than if it is not compressed. Once found a 1913 vintage 1911 magazine that had been loaded since 1918. I bought it in 1975. Used that magazine repeatedly until I sold it around 2015. Never a problem with it.
 

Johnnu2

Hunter
Joined
Jun 26, 2003
Messages
2,844
Location
NYS
Dear and Johnnu2,
I have fiddled with it some and have not got it back together. I did a search as Johnnu2 suggested and got some ideas. It will be a little while before I can spend some more time on it. I will report back. Thank you for your assistance.

1chessiefan
TRUST ME 1chessiefan..... It is a GIANT PIA to reassemble... GOOD LUCK

J.
 

Dan in MI

Moderator
Staff member
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Messages
3,485
Location
Davisburg, MI. USA
I took it home and was able to get the bolt to go back with a 22 cleaning rod and a rubber mallet. I had to drive the mainspring pin out with a wooden dowel and the mallet.

Ok that has a me a little concerned but we'll ignore it for now.

First, when flipped outside the frame does your hammer strut look like this?



IMG_4491.JPG



Can you do this and everything functions? (catch the hammer with your thumb when pulling the trigger.

IMG_4487.JPG
 

Dan in MI

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Messages
3,485
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Davisburg, MI. USA
If you can do all of the above then try full assembly. This is the part everyone whines and cries about.

Look in the backstrap while assembling. Hold the gun muzzle about 45*. Make sure the hammer strut is dangling. Catch it in the mainspring pocket. If the mainspring won't close. Don't force it. It should close easily to the last 1/8" then there will be minor resistance. If no resistance at all the strut is not right. If you get it together and the bolt only comes back 1/2" remove mainspring and try again. The strut is not right. The whole trick is to get the srtut in the pocket.

1655860678068.png
 

06dilly

Single-Sixer
Joined
Feb 24, 2018
Messages
182
Location
Minnesota
In case this helps, here's a link to a video I put together a couple years ago that may help you.



Some of these are just tight. Mine in the video is very easy but the concepts are the same. I have one 5hats incredibly tight. Once you get things aligned like Dan shows, just use a dowel crossways to force it back up. It'll go, just takes patience.

TomD
 

Dave Schwaab

Single-Sixer
Joined
Nov 2, 2014
Messages
128
I own several Mark IIs. They are my favorite shooters. The thing you must always keep in mind during the reassembly is the position of the hammer and hammer strut. They can be a bit finicky sometimes, but just keep checking the hammer & strut and you will get it.

By far, the best video I have ever found to illustrate the reassembly is:


Dave
 

Johnnu2

Hunter
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Jun 26, 2003
Messages
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Location
NYS
Now THERE'S some fabulous, detailed help for our new member. Great photography and PATIENCE are displayed to help a shooter in need....

J.
 

Dave Schwaab

Single-Sixer
Joined
Nov 2, 2014
Messages
128
I don't feel the need to make this little modification myself but some of you may find it worthwhile.

Here's the video of the installation:


And here's the link for the Hammer Strut Support plate:

Dave
 

Enigma

Hunter
Joined
Apr 17, 2002
Messages
2,511
Location
Houston metro area, TX
I field stripped my 1965-vintage (A54 grip frame) MKI Target recently, to do a detailed cleaning. It's been a L-O-N-G time since I had done so, so I took the time to watch a YT video on the subject first. Miracle of miracles, it went back together, RIGHT, the very first try! And I'll give a shout out to those who provided assistance for the OP. Mr. Ruger was NOT thinking about ease of assembly when he designed these pistols!
 

1chessiefan

Bearcat
Joined
Jun 3, 2022
Messages
15
Location
Ohio
Dear Dan in MI,
The hammer will go forward into the position shown in your first picture. The hammer strut looks like the one pictured. But the sear does not easily release the hammer. I am unable to assemble it as depicted in your second picture. The mainspring pin will not fully insert as shown in your fourth picture. Nor can I install the mainspring pin as depicted in your fifth picture.

While I was working on my problem child I took apart my other Mk II. I was able to take it apart and get it back together. I have had that pistol since the mid-1980s and never had any trouble with taking it apart and getting it back together.

What potential issues could have followed from using the cleaning rod to unlock the bolt?

Thank you for your assistance. I appreciate any further help you could provide.

Sincerely,

1chessiefan
 

1chessiefan

Bearcat
Joined
Jun 3, 2022
Messages
15
Location
Ohio
Dan in MI,
I have compared the parts in my other Mk II and my Mk I. The mainspring pins from the other pistols have the same problem. A person on another forum said he had a similar problem. He ground a taper onto a drill bit and used it to align the receiver and frame. I was thinking of ordering a t grip. Is the mainspring pin 5/8 inches?

1chessiefan
 

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