I saw it, but can't recall where. Picture a single piece ring set. But rather than bolted to the scope base in two places, it pivots in the middle of the base and the entire scope and one piece ring set are turned 90 degrees to remove the scope. So when the scope and one piece ring set are removed the scope base has a square swivel in the middle of the base. Put the scope/rings unit back on by orienting them across the barrel length, insert into swivel, turn scope and ring set 90 degrees and it locks. I think I saw it on a military rifle, just wondering how it would do for a H&R that has open sights and a scope, for a quick change. My description is from what I thought I saw...can't believe I did not save the webpage.
The isea is not to switch rifles, just on and off the same rifle.