I use H335 with pretty good success (less than 1/2 MOA at 100Y) in my .223 and 308. Just bought myself a Rem 700 stainless in 300 WM. Can't find any loads using this powder. Is it just way to fast for the larger cartridges?
H335 is pretty fast burning for a large-case like the .300WinMag. It's pretty identical in performance to Reloder15 and IMR3031...too fast a burner to get peak velocity before you start running into high pressures.
I don't load for the .300, but occasionally for the 7mmRemMag which is reasonably close in case capacity and bore diameter.
For the .300WM, I would probably stick with H4831, RL19, RL22, or something in that range. RL22 is a good performer for me in the 7mmRemMag.
To my mind (I prefer loads with slow-burning powders with as near to 100% density), RL-17 is a bit fast for the large-case magnums. I prefer the RL-19 & H4831 range too.
RL-17 is in the "4350" range on the burn chart. Alliant has never had a powder similar to IMR or Hodgdon 4350, RL-17 finally fills that gap. I haven't tried it yet, but it is on my options list for a few smaller cartridges.
If you prefer a faster burn rate, then RL-17 or any of the 4350s will work for the .300WinMag.
Thanks for the tips. I also came across a load table from IMR for their Trail Boss powder for rifles. They even have loads for the 300WM. I whipped up a dozen rounds with 20 grains of TB under a 150 gr. Hornady spire. Talk about a mild load! Sounds like a 223 out of a suppressed rifle. Lots of fun for target shooting. Saves your barrel from a premature death also. Decent accuracy, around 1 MOA at 100.