Tn Tom, Your 1st post you mentioned bedding the action and said; at 1st The groups tightened up then went "south" again. Struck me as curious. Did you change action screw torque? Did you remove stock and re-attach? Did you use a "stress free" bedding technique? Is it possible that your rear tang is contacting the stock and causing a different "set" each time you remove and replace it?Cause it seems you've been doing a lot of that. You seem to be a pretty thorough guy and this may not be the issue Just tryin' to help. Also, I've had problems w/ front rests and THOUGHT I'd fixed it. I switched to a Harris bi-pod and the groups shrunk significantly!! Used a "V" notched rear bag & slid to & fro to Lock in elevation. It worked real well for me. Again, not trying to be insulting but a good way to determine how steady your hold is can be determined by dry firing. Try it w/ your current rest. Shooting ten shot groups can be an exorcize in masochizm! How fast do you shoot ten shots? Barrel heat mirage could be coming into play. If you're like me, sometimes I don't see the forest for the trees ;D With all the talent available here (not me) somebodies goin' to come up w/ an answer. Keep on keepin' on .5" to .7" isn't terrible 4 a factory bbl.