I don't know where you live, nor do I know how competent a shot you are, no insult intended, but I would like to shoot these bad shooting rifles myself, partly to eliminate the original shooter and to evaluate the guns themselves. I'm not saying I'm all that great a shot but I do have 21 Ruger #1 rifles in various calibers plus a custom .223 "walkabout" gun based on a Ruger #1 action so maybe I think I understand these rifles just a little bit. I have a few M77s too.
I guess Ruger's standards must have dropped a great deal if they now consider a 4" group accurate. I remenber when they said 2" was their standard.
I'll throw a hint at you to try when shooting a #1 from the bench. See if that makes any difference. When shooting off the bench, have the gun on the sandbag or rifle rest if you have one resting with the front of the lever/trigger guard up againt that front bag/rest. It's gonna feel very awkward until you get use to it but that sems to work on most #1's. Another thing you can try is rest the gun on your hand which is resting on the sandbag/rest as if you were shooting from a field postion. Make sure in both ways to try that the read sandbag is in properly place. Sometimes the second method is better, especially on the harder kicking guns like the .375 H&H, .404 Jeffery and .416 Rigby. (Just as me how I know. :lol: ) Needless to say I don't shoot those very much.
As far as I am concerned, Ruger stating that a 4" group is acceptable is NOT acceptable in my book and if I were you I'd raise some hell on that baloney.
Just a thought. I don't know how old your gun is and if it' a red pad gun, it probably has a Wilson barrel. Some were not all that good and some flat out no good. I had one, a 7x57 #1A that had a throat that was way out of spec. It tooh a chamber cast to confirm it and Ruger finally did replace the barrel. It shoots good now. Try this. See if you can seat a bullet far enough out to contact the lands. If the bullet does make contact, we'll have to look at other ideas.
Here is an article that may help, but be advised that any alterations made to the gun will void the warrantee, unwritten as it is.
http://varminthuntinginternational.com/ ... ruger.html
Paul B.