Ruger M77 Problem

[dan512]

I have a Ruger M77 and recently experienced an interesting problem. This is a gun I take out once a year to sight in for hunting. This year I had extraordinary difficulty opening the bolt and then sliding it back to eject the shell. The bolt would twist about 90% of the way, but to lift it to where it was lined up enough to slide back took a bunch of force. After that, sliding the bolt back took me pounding the butt of the rifle on a table and "mortaring" the thing.
I was shooting new, factory ammo. It was actually the remainder of a box I used last year with no trouble. The gun was greased and has had nothing done to it since I put it in the safe last year.
Any advice or ideas?

[Jamnanc]

Clean grease out of chamber/barrel?

[dan512]

I did try that. The thing is damn is almost spotless. The only inclination I have is something to do with the trigger or firing pin re-set? I am an AR guy so these new-fangled bolt guns confuse me.

[vossman]

Sight base bolt/screws in the way? You'd probably see marks when you removed the bolt. Just a thought.

[BPTactical]

Check casings for signs of overpressure.
Check headspace.

Check your safety position as well.

[theGinsue]

Tagging to monitor this thread. Been shooting an M77 for 25 years or better and never heard of this type of problem. Interested to see what comes of this.

[AKA-Spook]

if I'm reading this correctly, I'd be taking the bolt out and then apart to clean and grease the firing pin/cocking mechanism.

[jmg8550]

Check casings for signs of overpressure.
Check headspace.

Check your safety position as well.

Overpressure was my first thought as well.

OP, new ammo, reloads? Does it chamber normally?

[SA Friday]

If something is jammed in the track for the winchester style extractor claw, the ring around the bolt, it won't want to rotate. Try some penetrating oil in that area and see if is loosens after a few cycles.

[tmjohnson]

Maybe you over tighten the screws holding the receiver into the stock. That could be flexing your receiver.