One thing I found out is Ruger has changed the twist rate several times on these guns.
So many that you can' t get a straight answer from them on the subject.
I' ve heard 1-12" , 1-10" and 1-9" .

That must explain why I had one that shot great , one that shot good and one that was fair.[:' (]

They can be helped some by using glass-bedding to tighten-up the fit between the stock and action, which is very sloppy in many of them. The metal stock liner should also be bedded as it tends to rattle around some too.

Also, replacing that wobbly rear peep-sight with a good after-market one helps.