i just started 375 ruger development today using 300 grain hornady btsp's and rl-17. i tested to 81 grains w/ the bullets seated to maximum mag length:
www.baitshopboyz.com/forum/forum_posts.asp?TID=19464&PN=1that's the data i have so far... more coming as i get more. so far, i am really liking rl-17 in this application.