Boy, you're in luck - I had dumped all of my notes in the recycling bin but forgot to set it out this week, so I went and dug them out.
The rifle has a long throat, trying to seat to the lands leaves most of the bullet outside the case. So instead I just seated them all one caliber deep, i.e. case length + bullet length - .284 = OAL. Here are the best loads for accuracy with the three bullets I tried.
Hornady 139 BTSP, 47.0 H4350, avg. 2734 fps.
Hornady 139 SP (flat base):
47.0 H4350 2751 fps (best accuracy)
48.0 H4350 2806 fps
48.5 H4350 2828 fps
Sierra 120 Spitzer (seated .250" deep) again, that magic 47.0 H4350 for 2725 fps.
Overall the Sierra 120 outshot the two Hornady bullets but just by a smidge.
I've loaded up to 49 grains H4350 with both of the 139 grainers for about 2850ish fps, but as the above shows best accuracy was at about 47 grains. Didn't do a lot of load workup for this, just started with H4350 and the recommended charges in John Barsness' "Loads That Work", found the loads it liked and then went and shot it.
Hope that helps some.
