Usual culprits would be copper fouling, loose stock screws and bad bedding. If it were mine, I’d hit it with several applications of a foaming bore cleaner, and once the blue stops and the carbon is gone, get a good look at the throat and crown. If they look OK, I’d pull the action, look at the bedding, checking for cracks or obvious problems, then retorque the action screws, and see if the barrel is rubbing the stock anywhere. Once all that is good, take it out and shoot it to see if you still have that problem. I’ve made several guns shoot acceptably that way.
What vintage is the gun? I had a tang safety Ruger in 257 that alternated between that and five inch groups, so I figured the barrel was trashed.
Old70
