I'm with you RC, That does seem less than good.
The crazy thing is I use about 4.8 gr of TB for 125 gr LRNFP and the PSI ain't hardly anywhere near 15,000.
I shoot alot of Trail Boss in my revolvers and lever guns, but for 148 LBHWC's, I think I'll stick with the generic charge of 2.8 gr of Bullseye.
LGB