Not exactly "one cure for all ills" but a good starting point. I've been twice confronted with the situation. The first time the cartridge holder was pulled and the contours where it meets the cartridge rim very modestly softened with a fine stone. The second time, removed and found the bore the holder, spring and follower were inserted into were packed with residue. These parts are shrouded in the action and blow by tends to accumulate, restricting its movement. If you shoot your 77 a lot, stripping and cleaning the bolt now and then is easy and keeps the rifle happy.
The only other feature contributing to ejection is a sturdy spur integral to the trigger guard and is unlikely to be problematic.