Back in the day I used Leupold rings and bases. One of the rings twisted in a slot in the base. Are these used anymore?
I used them most of the time unless I'm using a Talley one piece or a Picatinny rail. I prefer the dual dovetail setup with twist-in rings both front and rear over those with a twist-in ring in the front and a screw-adjustable rear after a period where I had a number of sets of the "standard" (front twist, rear adjustable) rings come loose in the rear. I think it was a manufacturing flaw as several friends had the same things happen at about the same time who had never had issues before.
