Gary, good point. With the Signature rings, I've had return to impact as much as 1 moa off, but never worse. My .220 Swift returned to poa as close as I can shoot, but a 6 BR was off poa 1" at 100 yds.. With Weaver Grand Slam (rigid) rings, and Grand Slam bases, it appears that they can return to impact within 1/2 moa pretty consistently. The Signature rings have 1" scopes, and the straight Grand Slam combo's have 30mm tubes. I don't know if that's a factor. Also, the 6 BR has aluminum bases, not the steel Grand Slams.
I think somebody mentioned it, but a big feature of the Signature rings is that they WILL NOT mark a fine scope. I put a set on a friends custom lightweight .300 Wby (a fair kicker) with an older glossy Leupold scope that I absolutely did not want to mark. I've got another set ordered for a 30mm Swarovski that I also do not want to risk marking. Easy call.
Tom