Jester,
I looked for one of those 358009 moulds for one year (eBay, Gunbroker etc.) and never could find one, so I finally gave up and designed my own through Mountain Molds. With pure Lino it pours 270gr with GC and lube, with Lyman #2 it pours about 280gr with GC and lube. My go to load for this is 42 grs of IMR 3031. The "other" powders (4759, 4227 & 4198) work pretty good as well but I like to try and fill the case a little more. Your 1:14 twist should stabalize the 358009.
Like I stated my Whelen is very long throated. The COL "should" be about 3.340 (standard 30-06). With the Speer 250gr seated 2/1000th off the lands my measured Whelen is COL 3.407. That length will not fit into my 1903 magazine so I have to reduce COL to 3.358 to get it to feed. That is a pretty good "jump" but it does not seem to impact accuracy. [All COL measurement made with the Hornady COL gage]
Best load accuracy for my rifle is with the Speer 250gr with 54gr of RL 15, Rem Case, Rem 91/2 primer. Right behind that is 53gr of IMR 4895 (same case and primer). [I know the Speer manual shows 49gr max with 4895 but their #7 manual used to show 57grs as max. My rifle does not produce flat primers until I hit 55grs of 4895 so I reduced it 2 grs off that and get very normal primer indications. I suspect my long throat and seating adds enough to the case capacity to make 53 grs of 4895 a "workable" load. I have not tried to "stretch" the RL 15 loads, because I have shot that powder much less than 4895.] IMRs 4064 and 4320 seem to work well but there is no significant improvement in my rifle over what I was getting with 4895.
With 4895 I never could get "good" accuracy out of the Hornady 250gr RN. Like I stated previously, the Hornady 250gr Spire Point works well. It may be that my long throat is just too much of a "jump" for the RN to produce accuracy in my rifle.
Barstooler