Does anyone have 375 Weatherby loding data with S365 powder?

Thanks

In my powder burn rate chart, S365 is bracketed by IMR4350 one place above it & H4350 2 places below it so I would guess you could safely start with start loads for these & work up for your rifle. Try going to Hodgdon & having a ferret around, they have loads for H4350 in there for pretty much the whole range of bullet weights.
Steve.

Burn rate says nothing about density or energy per unit measure. Unless it is known that all of these attributes are shared by 4350, using 4350 load data is not indicated.
.

Got a better idea??
While I can agree that it would be unwise to directly extrapolate data from one powder to another as far as top loads were concerned based on burn rate, in this case I would feel totally confident to use the start loads, as I mentioned in my previous post, for a powder of similar rate, especially seeing as we're talking a fairly slow burning powder. Reloaders do this all the time when faced with data that is incomplete for their calibre, wildcats & obsolete powders.
Steve

Bushbuck 1

Use .375 H&H data as a good minumum for your .375 WeM loads. I shoot a Brno re-chambered from H&H and have scads of loads worked out, including for RHINO's (but not with Somchem powders). Work up your loads -- a 4 to 5 grain spread ought to work, looking for pressure signs and chronographing speeds.

Mauritz Coetzee is a great source -- Pretoria gunshop (something like L&W).

My Somchem book shows S335 instead, but thats a pretty fast powder for what you want.

Bushbuck1, scroll down this page, GS Loads, it gives some start loads with GS custom bullets for a variety of powders, it may help you make your choice. Interestingly, AR2209 which is an Aussie made powder which is sold in the US as H4350 is listed the same as S365 , both of which are listed 2 grains heavier than H4350. Go figure Theres some interesting info on these pages too.
Steve