That explains it... I finally got around to checking the twist and it ends up being 1:16. I guess that I shouldnt expect it to stabilize 50grain SPBT's of any brand. It looks like I will be trying 35gr vMax, and CW's flat point suggestions next (Midway has them). I ordered a box of the 45gr Barnes X too, for postarities sake, but I dont expect them to stabilize from a 1:16.
The 1:9 barrel came in, so I know it will shoot what ever the 1:16 won't.
Steve