Put these mounts on a 338 Lapua. Have been very stable. I do not remove these mounts so I can not say anything about the return to 0. But I love the six screws per each mount. Did not have to lap the ring very much to get them perfect on my gun. Savage 110 Ba.
I use them on my Savage 308 and they work good for what there intended for. Identical to the Weaver tactical rings (just renamed to BlackHawk exclusively for Cabelas). Seem very durable and have had no problems holding zero at all. Overall, pretty good rings for the price.
First of all, these are the same as the Weaver brand Tactical Rings. Just different packaging. Good solid rings just a little less robust than the Burris model. The base is a little smaller so it fits better on standard bases.