Re: 338 win mag
We've used H-4831sc, 78 grains, Federal 215 primers in 4 or 5 different rifles. The same Rugers you have, a Winchester and a Sako. It's a max load in Noslers book, but you really can't get much more in the case anyhow.
Mostly we've used H-4831 sc because we always have some on hand. Generally we've loaded it for youngsters, and gradually move up to heavier bullets. The 4350's will likely give more velocity, but if your goal is managing recoil with lighter bullets 4831 will give you an honest 3000fps. I've ran the 180 Accubond in my 338 RUM to 3500fps without the wheels falling off so drive it harder if you need.
Devastating on smaller deer and antelope, but I've never challenged with something big, or a hard test medium.
If you push it I think you'll be pleasantly surprised at how far it can be effective. If you're primarily looking for meat, or pelts, I'd make another choice.