OK, I'll add to the kafuffle. Tang safety on the wrist. I HAD a 243 like that and it would absolutely not shoot accurately. I could get groups down to two inches, but most were worse and rarely was one better. It was well bedded, so it wasn't that. I have left over's of every weight bullet I think they ever made in 6mm.
The information I got was in these older 77s, Ruger purchased the barrels. Some were apparently OK, and I can assure you, some were not.
Also, in the hunting field, my hand would accidently push the safe to off, without me knowing it.
I wrote a hardluck story to Ruger about the safety coming off, thinking they may consider it a liability issue and do something about it. They told me to take it to a gunsmith and maybe he could make it stiffer!