Barnes cautions against using X data for the TSX bullets so I'd double-check your load data against the latest manual (#4) before stuffing your shells. Especially if you are playing near the max load charges.
Last year dug my 25-06 out of storage and had to restock my 100gr .257 X Flat Base bullets for it's pet load. Yeah I stocked up a long time ago...
Turns out that I can only get the new TSX style, and since Barnes cautions against using the data for the original X bullets with the new TSX bullets I borrowed a friends new Barnes #4 manual and grabbed some data, which was close to but different than the X & XBT data from my copy of #3.
In the .25-06, my 100grX pet load charge was within the range listed in the latest manual so I stuck with it. the TSX was about 150fps faster given the charge weight, but I've no idea on the pressure since the load was about mid-range according to both manuals.
Also in my rifle, it didn't particularly like the original XBT bullet (it grouped better with the XFB instead) but the TSX groups completely different than either of the older bullets...I haven't taken the time to fine tune that load to the new-style bullet yet.