Looking for some date on this cartridge..... The loads I was proided for testing a new build is 100 gr Reloader 15, 570 gr bullet.

This would SEEM like a fairly moderate load., but I'm always a bit cautious.

Any toughts?

Best I could do Duane.

I note the 570 gr load is "not pressure tested" Howefver ,I see a 115gr loading with 600 gr. bullet.

The data may not be exactly what I wanted, but . but I feel the question in my mind has been sarisfied.

Really appreciate the help seeya

Duane, I have burned a lot of RL-15 in my .500 A-Square, although I now use RL-17. Both work fine.

RL-15 can vary quite a bit from lot to lot. My maximum loads, which have gotten me 2,400-2,500 fps with 570 grain Barnes TSX bullets, have ranged from 110 to 115 grains of RL-15.

This is using MAST/BeLL brass formed by me in CH4 dies from .378 Weatherby basic cylindrical brass head-stamped for me by Quality Cartridge.

I always use Federal 215 large rifle magnum primers.

So, I would think 100 grains would be okay to start with, but probably very light for caliber. I would be inclined to start with 105 grains myself.