I read Alliant's web site info last week, and while RL-17 data is there for almost any rifle application but the largest magnums, it seems most beneficial to moderate capacity ctgs, esp those 4064 or faster powders. Not much reason to use it in H&H case magnums, but maybe it would shine in .458 and .450 Marlin especially.
About 12 yrs ago I picked up a takeoff rem 700 bdl barrel in .35 whelen. Mounted it up and fired it for about 30-40 rds of handloads using 200gr Rem Core-lokt and 250gr speer spitzers. Nice, and a good woods-carry rifle up where I live; but was more intrigued by the .338/300 for power.
Yet, a couple weeks ago got a .35 whelen AI custom barrel that was like new in a deal, plus dies and 200 more pcs of brass. Now with about 500 pcs of brass and about 400 bullets, plus the new powder to work with; seems like a great opportunity. Oh, yeah.... Have another 400 170gr gold dot and sierra pistol bullets also.
Eric, Would sure appreciate your sharing some of your starting point data. If you haven't read the German Salazar article over at 6mmBR.com, it is worth a read for sure. I will have to save this one for reference, but absence of pressure signs with compressed loads and 300fps gains from the .284 Winchester are just WOW!
Was thinking of a .338/284 for a standard boltface short bodied ctg, as I am not a velocity hound; but saw an article by McPherson on wildcatting the .284 and in there he suggests that .375 is the optimum neck-up for the .284 unless you AI the shoulder and then .411 is feasible.
The .375 does have all the chey-tac activity going for it, so maybe lost river ballistics has bullets?
Aside from 225 Sierra and Nosler ballistic tip, there just don't seem to be any decent bullets to work with in .358 cal... Have you tried any cast bullets???