375h&h guidance - bullets, dies, and brass

[benchracer]

Quick update.

Unfortunately, it appears RL-15 has become unobtainium just after I got my suppressor out of jail and my barrel cut to continue trials.

I have copious amounts of varget and some H4350 that I will run a few trials in initially.

That being said - it appears the heir apparent of RL-15 is RL-15.5.
Does anyone have experience with this in 375h&h in a 270 TSX?

I am just beginning to work with TS 15.5, but not in 375 H&H. I am finding that it is not as slow burning as I had expected. In .308 Win, powder charges are staying within one full grain of VARGET and picking up about 40 to 50 fps in muzzle velocity. TS 15.5 will sit between VARGET and H4350 in burn rate, but it is less bulky than H4350, so it will take up less case volume.