As it says on the tin, I want to find out which powders will work well for a 300 gr TSX in the 375 Ruger. GG has a 20 inch barrel.

I want an available powder (i.e. not Alliant), minimal compression, and preferably moderate/low temperature sensitivity. I'm only looking for about 2500 fps.

Searching AR indicates Varget and H4350 might do. Haven't seen H4895 mentioned. My QL calculations, not to be trusted obviously, look like this;

68.25gr H4895, 67 kpsi, 2500 fps
70.25gr Varget, 67 kpsi, 2500 fps
76.7gr H4350, 65 kpsi, 2500 fps, 108% fill
68.25gr 8208, 70 kpsi, 2500 fps

Are these pressure predictions way off? What do y'all think are safe max loads with these powders?

thx

I don't have your calibre but predict that H4895 and Varget will give you less-compressed loads (than 4350, at least) and good heat tolerance. Why, the latter? Because last I heard those Hodgdon powders were all made in sunny Australia and have a good reputation for withstanding torrid climates.

The faster powders are also more likely to give best performance in your short barrel.

The pressures quoted seem a bit high for tropical loads, though.

So I just compared Hodgdons online data vs QL for .375 Ruger, 80.7 grains of H4350, 24 inch bbl;

MV; 2,660fps Hodgdon, 2597fps QL

max chamber pressure; 59.6kpsi Hodgdon, 61.3kpsi QL

so not horribly off.

Changing bbl length to 20in in QL results in 2492 fps.

So QL seems to think that N550 is pretty good for the .375 Ruger and 300 grain bullets.

I usually ignore VV powders because products from that part of the world were unobtainium during the lockdown. I checked using AmmoSeek and it turns out N550 is readily available now.

I ordered an 8 lb jug, as N550 also works great for 100 grain bullets in .243 Win, in case my .375 doesn't like it. If QL is to be believed, N550 is a mouse-to-moose powder!