If you havn't done so, you may want to go to the Weaver site and read up on the types of rings they offer. Decide what you want for your shotgun, aluminum or steel, then go from there.
For years I've used their standard Detachable Mount. I've used other brands as well and have had few issues with any I've tried. Back in the day the Weaver Detachable was a mainstay for the average person and they are still a good unit.
Having both cap screws on the same side of the ring, keeping the scope straight during installation can be a challenge. I've seen fellows mount the rings opposite of each other.
They now offer a cap that has the screw on both sides. On that version, the bottom of the ring is aluminum and the cap is steel. With the screws on each side, mounting is much easier. I have one set (forget at the moment what rifle its on). They seem to work fine.
I have tried the Grand Slams on a couple occasions and do not like them. I found the workman ship to be very rough. There were machine marks. They were also heavy and a bit clunky for me.
If I need an extension ring, I use Weaver. I really like how they fit and are designed.
