Mark II Stainless Bull Barrel Roughness

Discussion in 'Ruger Rimfire Forums' started by ccryder, Apr 30, 2016.

  1. ccryder

    ccryder New Member Lifetime Supporter

    I've had this Mark II for years and loved to shoot until, I started down the 22/45 Lite road. Periodically I shoot and then clean all of my firearms. Since I have been shooting my modified and smoothed 22/45's, the Mark II felt really rough while pulling the bolt back.

    Since I had it torn down I started to see what may have been contributing to this roughness and higher force to retract the bolt. When I looked at the top of the bolt I noticed that there were heavy machining marks on top of the bolt where the return spring stirrup rode. A few stokes with a file and stoning with 400 then 600 grit stones, I pulled out the Dremel and polished those two narrow surfaces.

    On the bottom of the bolt, there is a rub surface that pushes the hammer into the cocked position. This rub surface also had the same heavy machining marks as the top of the bolt. Again with a few strokes of a file and then 400 and 600 gritstone S it was ready for polish.

    After cleaning up the machining marks on the top and bottom of the bolt, I was amazed at how much easier it was to cycle the bolt. I could feel the difference while shooting and this aided increasing my fondness for this Mark II. I don't know if Ruger has improved their machining/finishing operations on the 22/45's or, is the stainless steel just more labor intensive than blued components.

    Now I have 4 Mark II/22-45 that are all easy to cycle manually or firing with less vibration. Note: minimal metal was removed, only 0.001"-0.003" to make a world of difference.


    Neil S.