This is for the 77/44, 77/22, 77/357, 77/17 with the two piece bolt body.
Here is a link for the shims.
https://www.triggershims.com/ruger_m77.phpThe Volquartsen trigger spring/sear does a lot for accuracy in these rifles as well. Normal factory trigger pull is 6.5# or over. The spring/sear brings it down to about 2.5# usually.
I tried the bolt shim kit in my 77/44. It had not been fired much when I bought it. I could not even get the thinnest shim to work with it, so it was locking up pretty good as it was. I ended up selling the gun, and included the shim kit with it.
After every 50-100 rounds, the gun can be checked to see if it will accept any shims or the next thicker shim. It simply is taking the play out of the forward floating section of the bolt, which can help with accuracy.
I don't believe the standard 77 Hawkeye rifles can be shimmed.