Problems With Ruger Mark III Mainspring Assembly

Discussion in 'Ruger Rimfire Forums' started by Jim1952, May 3, 2017.

  1. Jim1952

    Jim1952 New Member

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    I've had my Mark III for about 10 years and have never had any issues with reassembly after cleaning, but I made a dumb mistake and I need help. I inserted the mainspring assembly housing wrong, and it is now stuck, but loose. The bolt stop pin is not visible through the bolt, it is somewhere forward of that position. The bolt is in, and moves freely, but I cannot get it out.

    I recently installed a Volquartsen trigger kit (which works great), so that should not be the cause of any problems. I contacted Ruger, and unfortunately they will fix it, but remove my new trigger if they get hold of it, so they are not an option. Does anyone know if I can take this thing apart without first removing the bolt from the receiver, and then removing the receiver from the frame? I'm thinking I can start by removing the grips and then tap the sear pivot pin out. Hopefully this will give me access to whatever is hanging up the mainspring assembly housing.
     
  2. allenr

    allenr Member

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    Volquartsen makes a mainspring assembly for the MK III. Do they must now how to get it in and out. Maybe you can get some guidance from their techies.
     

  3. Pancho_Villa

    Pancho_Villa Well-Known Member

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    I don't have a MK III, but do have 3 of the MkIIs and have had several MkIs. From what you describe, it appears that the bolt stop pin missed the lower hole in the frame. There is some space there for the hammer and hammer strut to operate. If the hammer is in te "fired" position and the bolt stop pin was wedged behind it, you would probably not be able to move the bolt at all. The hammer would be against the firing pin and would stop bolt movement with the bolt stop pin wedged behnd it. This doesn't seem possible cause there is should be enough space behind the hammer to allow it to move infront of the bolt stop pin. So, the hammer has to be in the cocked or rearward position.

    Now, if the hammer and strut were in the cocked back positin with the bolt stop pin wedged behind it, it would seem that the bolt would move free as you say. However, the bolt stop pin may be sticking up high enouhg to stop the rearward travel of the bolt at some point.Tha would keep it from coming out all the way. That sounds more like the condition you describe.

    It would seem that you may be able to get the sear to release the hammer to go forward which could release the bolt stop pin to come out as it should. this is unless there is not enough room for the hammer to travel forward. It would even be harder to do if the hammer strut actually made contact with hit's "notch" in the main spring housing. If it did, the hammer and strut are also under mainspring tension.

    From what you yaid, the bolt moves free to a point. So, the hammer must be cocked. Can you release it or get it to move forward? Can you tell if the hammer is under spring tension? If it is under spring tension, you really have a prblem. The only way to release the ension is to get the mainspring housing out, which you can't do.

    I assume you have had the receiver off the frame cause you installed the new trigger. then You know that the travel of the upper to loack the lower on is only bbout a quarter inch. It is on my old guns. With the hammer being in th cocked position, there is nothing restricting forward movement of the receiver from that. You also have the bolt moving free in the upper. The only possible restriction there is the location of the bolt stop pin. It appears that the receiver should come off the frame. The only way that it would not is if you got the bolt stop pin through the lower guide hole in the frame and somehow got it out of line before it came out the top. It would be hard to see if you got it through the lower hole unless you can see it through the top hole. if the slide stop pin is not in either one, it seems tht the top receiver should come off the lower. However use this information at your own risk. I am no certified gunsmith, nor do I claim to be one. Just a gunshow gunhack. Fix the clunkers and get them out ont he table and in circulation again.

    I have seen one like that. Somehow, a guy I worked with got the pin through the first hole and bent the recoil spring and guide rod cause he could not get it through the second hole. He managed to get it in by force and put it back together. However, the gun did not work cause the bolt stop pin was wedged between the recoil spring and the upper receiver.. I had to get back into it and managed to straighten the gude rod enough to get the recoil spring and bolt to work where he could use it. We later replaced the part.

    I have seen my sare of "paper bag" MKIs & IIs at the gunshows. People bring them in and most of them just can't get the guns back together right.
     
  4. Jim1952

    Jim1952 New Member

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    Thanks Allen, Volquartsen will be my last resort.
     
  5. Jim1952

    Jim1952 New Member

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    Thanks Pancho, these are all helpful suggestions. I am aware that the hammer can easily move upwards and hang up the works, so I have tried to get it to fall (if it is not fallen) by tapping with a rubber mallet. Whatever is going on, this has not helped. A lot depends on what kind of access I can get to this area when I remove the grips. I agree that the stop pin is high enough (wherever the heck it is) to be interfering with me sliding the bolt out.

    Now, I know there isn't any mainspring tension because I never got in in far enough to engage the latch and extend the mainspring into position. I can flap it to and fro, but as I noted, even though there is travel up and down, it only falls just so far.

    This is going to be a Saturday project in which I'll either get it right, or give up and see If Volquartsen will agree to figure it out for me.
     
  6. Pancho_Villa

    Pancho_Villa Well-Known Member

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    That slide stop pin has to be wedged between the side of the upper receier and trhe recoil spring & guide. Just seems like you could drive the upper off if you did not get it through the lower hole in the frame. But only you could see that, maybe

    It's gonna be a slow one to prevent any samage in either case.
     
  7. Jim1952

    Jim1952 New Member

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    Thanks Pancho, I finally fixed it. In looking through older posts on this topic I found this: "To fix a seemingly stuck mainspring system, you must move the hammer forward. To do this, insert an empty magazine--make sure chamber is empty--hold down trigger and swing the gun up and forward. As if you had a ping pong ball on the muzzle and we're going to throw it forward.

    You will not feel the hammer swing around--likely, but if you do that multiple times maybe at the end of the motion hitting the muzzle on your hand or some other padded surface, the hammer should move forward and allow you to disassemble as usual".

    Well, I had tried this earlier, but the magazine would not insert. This time I did some extra tapping, wiggling and praying and somehow what had not worked last Saturday worked today. The magazine went in, I was able to shake the hammer to the forward position, and the mainspring could be removed, and then installed properly. The problem had been that the hammer needed to be in the forward position. Everything is installed properly now, and I am good to go.

    This all happened because I forgot to remember to RTFM. Once I had installed the Volquartsen upgrade I had it in mind that this process would now be so easy and straight forward that it would not be necessary for me to read the steps each time I put the gun back together. The upgrade (really just making the Mark III more like a Mark II) allows me to pull the trigger to drop the hammer without inserting a magazine. So, it's a little easier, but you still have to insert the mainspring properly. Once I did that wrong, all bets were off. So, as if I needed the reminder, RTFM every time.
     
  8. Mrdjones602

    Mrdjones602 New Member

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    You're a LIFESAVER!!!