Anyone have any data for the 338 RUM and RL25? My Alliant manual doesn't have the RUM cartridges, looking around on the net, figured I'd aske here.
Got my wildcat conversion back from J Ricks, and the case is pretty similar to the RUM. Seems like a good place to start.
John was kind enough to do some pressure testing, but what I got was mostly RL19 and the like. I'm thinking RL22 will hit the nail on the head, but have a can of 25 to try.
Can anyone help me?
Thanks.

Nosler Manual 5th ED. lists 98 grs R25 and the 225 gr partition at 3227 fps as a max load. I got this velocity with 96 grs and stopped there.

Same source lists 91.0 grs R25 and the 250 gr spitzer at 2990 fps as max.

Thanks Sabot. I was planning on something like 93-100g for the 250g, and 88-95g for the 280g, .25g increments. Maybe I'll drop down 2g though.

I think you'll find that RL25 works better for bullets 250gr and larger.

Well, this is a .358", so 250 is 225, if you know what I mean. I'll be working up loads for 225, 250 and 280g, and with a can of 19, 22 and 25, so I should be ready.

Wildcat conversion, similar to RUM. 358 caliber.
You dodn't miss it, I just didn't tell the whole story.
But hey, if anyone has any data for a 358 RUM and RL25, I'd sure take it!!

Not load data, but quickload stuff. Took 358 STA upped case capacity to 115gn? 26" bbl? 3.6" cartrige length?
RL25 250 Woodleigh
100gns 103% 2950fps 51.5 ksi
106gns 110% 3120fps 63 ksi

RL22 250 Woodleigh
98 gns 100% 2980fps 55.5 ksi
103 gns 105% 3130fps 65.8 ksi

RL19 250 Woodleigh
96 gns 100% 3000fps 60 ksi
99gns 103% 3090fps 66 ksi

I don't know if this will be close or not?????????

Another approach, assuming that you have a full length RUM case and not the slightly shorter 338 RUM, is to drop a couple of grains below the 375 RUM data, OR use the 375 RUM data for a 270 grainer for your 250:

Noslers 5th ED says you can make a bit over 3000 fps with a 270 gr bullet with max loads of 96 grs of IMR 4350, 101 grs of H4831SC and 102 grs of IMR 7828 in a 26 inch 375 RUM.