The only reduced load I've used in the .375 H&H was suggested to me by Ingwe, who used IMR4227 with the 220-grain Hornady flat-nose--which was designed for the .38-55 but is now discontinued, or at least production has been suspended.
Anyway, the load was around 35 grains (can look it up if somebody's interested). It got around "high velocity" .38-55 ballistics, 2000 fps or so.
I wanted to use the load because I was planning an all iron-sight safari, and one of the rifles I planned to take was a Ruger No. 1 .375 with a NECG aperture rear sight. I would use full-power 300-grain ammo on the safari, but wanted a practice load that would shoot to the same place. I tweaked the powder charge until that happened, then shot a bunch of prairie dogs out to around 150 yards with the 220s--and they splattered PDs about like a .22-250. (I am sure they would have worked fine on deer, too, just like the .38-55--but never tried 'em.)
Anyway, am sure a similar powder charge would work fine with 235 Speers. The only problem would be finding some IMR4227!
