I ran some reduced loads for my 375 ultra using AA5744, I think they're in thier manual, but an e-mail to them will get you load data too... Kinda fun to shoot, and make nicer, cheeper fouling/rough sight in rounds than full house.

I also have a load lifted off the web, but untried, using IMR 4064, but wouldn't know where to start for charge weights on the 300rum...

John

"If a little's good, a lot's better, and way too much is just right!"