Someone may have mentioned this already and I missed it. I have a M77 about the same age, I didn't buy it new, but it was only a few years old when I got it. It was my dependable workhorse, however, about 4 months ago I took it to the range to check my zero (for years I've taken it with me on hunting trips as a backup). This time however, the shots were all over the place and I couldn't figure out why. It turned out that I had two cracks / breaks in the stock, a visibly small one at the end of the tang and a larger one that was only apparent when you removed the action from the stock, a piece in front of the magazine well was broken. The gunsmith was familiar with the inherent problems of the M77 stock and after I described my problems, and he had confirmed that there weren't any other obvious problems (all mentioned in the prior posts) he removed the action and showed me the breaks / cracks. Fortunately he had an old used Ruger stock on hand and was able to glass bed the action. The gun shoots better than ever. So, check the end of the tang for a small crack and remove the action and inspect the stock. It might be that that is the problem. It's been a great gun, it's taken antelope, deer and elk.
