This stainless Mini-14 was rented at LAX Firing Range in Los Angeles. It seemed to be fairly new. Ammo was PMC 55-gr ball, standard stuff. From what I've seen in the Ruger website, the rifling is suppose to be 1:9 which can stabilize the 55-gr load. This is the worst keyholing I've seen. Wanna kill these ads? We can help!