I'm going to check the mounts & rings again just to make sure. I don't know what else it could be - not with a rock solid setup with a lead sled. I've use corelokts & lightfields in the past in different guns & had excellent results. Figured 1 of the 3 would group better than that. I checked with 2 reputable dealers before getting the BSA & they both swear by BSA, mostly because of their no questions asked return policy - but why are they so quick to send you a new scope if they have a reliable product.........