Fritz, I shot them both today
the 338 was pretty accurate but went transonic....8.7 gr Alliant power pistol w/250 Scenar, so its going to be very efficient.
I didnt have a scope on the AR (I made the 308X39 barrel for an AR) and was just checking for a load that cycled....9.5 gr VVN 110 w/220SMK , magazine length,cycled a 16" w/gas port in pistol position nicely... I think it stayed subsonic too.
Gotta get out the chrono and plan to spend a day at the range, but its looking real good at this point. I think I also need to get Quickload, but I'm not sure how difficult it is to learn.
I put most of my effort into testing a hotrod 20 cal (20BRX) today....its going to make some coyotes very unhappy.