I've been shooting H4831 in 270's with 150 gr bullets for 35+ years. I don't think current production H4831 has as much "energy" (for lack of a better term) as it once did. When piezo electric pressure equipment came along it indicated a lot of the old max loads in the 270 were over pressure, and those published loads were reduced accordingly.
I have a 1993 M700 ADL, SS Mtn rifle that I used to shoot 59.1 gr of H4831 and 150 gr NPt. Even back then it was a stout load. Out of curiosity, I have attempted to work up to that load using different lots of H4831. I can't get close to 59.1 gr without plenty of pressure signs. I dismantled a bunch of 270 rounds loaded a long time ago that had H4831 produced in the mid 90's and have that powder set aside.
Now that RL26 has come along and changed the game for the 270 with 150 grainers I haven't pursued it, but one of these days I might give it another try with that old batch of mid 90's H4831.
Last edited by alpinecrick; 11/17/19.
