I have a Ruger M77 Ultra Light ,I have never shot factory ammo in it but I have many handloads for that gun, it is one of my favorite . I have taken Many deer with it. Mine is the older, pre Mark2 model. It has been bedded and free floated.My favorite load is 120 gr.Nosler Partition,51.0 Gr. Ramshot Magnum,Federal 215 Primer,OAL 2.945. This load shoots 1" groups out of A 20" barrel.