Ruger Mark II 6 -7/8 Government lock back probs on last round

I've got a mint condition Ruger Mark II Government that I've had for around 5 yrs. Shoots great and never fails to feed. However on the last round...it doesn't lock back fully. It looks like it's locked back, but it's not all the way. It jams on the mag follower and I have to manually pull the slide back (about 1/4 inch and sometimes it takes quite a bit of force) to lock the slide fully open. Last week I bought 3 NEW Ruger factory mags. If I put an empty mag in and pull the slide all the way back, it locks fine. Does this on all 5 of my mags. I thought maybe the ammo I'm using is not strong enough to fully kick back the bolt. So I tried Federal, Winchester Super X, Thunderbolt, and even Wal-Mart Remington......same result.....all feed fine, shoot fine, but on last round it jams up on the follower.

Has the gun always done this, or has it just started having this problem recently? Does the bolt seem hard to pull back even when the gun is empty and without a mag in place?

I know it might sound too simple, but have you field stripped the gun for a good thorough cleaning? Rimfires are notorious for getting 'gunked-up'. Try field-stripping, cleaning, and a light oiling of the bolt and see if that cures the problem...... Also, check for any burrs on the bolt and inside the receiver.

Let me know if this works for you, OK? Good luck!

Mark

I had the exact same problem with my 6 7/8' target model. Turns out that the last-shot hold-open piece was messed up something terrible. The bolt catching on the mag follower indicates this as the part in question is lifted by the button on the magazine. If the hold-open is hard to actuate manually, the mag definately doesn't have enough force to lift it. With the barreled receiver off of the grip frame, insert a mag and see if this piece is moving upward and examine its condition. If it looks anything other than smooth on the sides, consider replacing it. HTH