Does anyone have any pet loads for this combo

I'd say start at around 74 or 75 grains and go from there. I had good luck with 75-77grs of RL 15 behind a 270 gr TSX in three different .375s through the years. The best charge weight varied from rifle to rifle, with 77 hrs. Being a bit on the warm side for one the rifles, but the TSX is a longer bullet than you're using and ate up some space. Best of luck!

I'll let you know I just loaded some test loads today with 72 grains Reloader 15 and 270 grain bullets.
Trouble is I am about 20 loads away from being "out" of RL 15.
These should be mild as I'm pushing 300 grain Barnes TSX with 71 and 71.5 grains of RL 15.
And 300 grain Nosler Partitons with 70-71 grains.

What kind of velocity should I get with 74grs of R15

Quickload shows 74 grains as a 63500 psi load at 2783 fps, gives the warning not to use this load over pressure.
It shows my loads as over pressure as weel but I'm not seeing any pressure signs in my rifle, yours may vary use caution.

Thank you,I think i try about 72 grs