I have been looking at the older posts and also reloading data for the 375 Weatherby recently and it seems that with a TSX it is not likely you can get 2700 fps (24 inch barrel) without over-pressuring the thing, but with a Swift, Nosler etc, it is rather easy to do so. I haven;y seen a direct comparison TSX vs Swift, but that's what the data seem to be saying.

Would like to hear if that is pretty much what you reloaders are finding. I have an M70 that I may rechamber to 375 Weatherby but am doing footwork first.

Gracias.

I assume you are referring to 300gr bullets as 2,700fps is easily attainable with 270gr TSXs in a 24" barreled .375 H&H.

I have not used Swifts but I can get 2,800fps with a 300gr TSX in my 26" barreled .375 Wby. I would guess that 2,700fps should be no problem in a rifle with a 24' barrel.

One other thing, H4350 Extreme is THE powder for the .375 Wby. I would start with that one.

Thanks CR. Yes it's the 300 gr I mean. Also thanks for the powder tip. Any chance you could share your pet load via PM or otherwise?


Thanks.

You can buy factory 375 Weatherby ammo that will give 2800 fps with 300 gr. Noslers. You should be able to easily get 2700 and above reloading with the 300 TSX, even 2800 fps. Barnes offers a load for the standard 375 H&H for the 300 TSX giving 2655 fps, 24" barrel, and 75 grs. of Vit N540. With the 375 Weatherby you should easily surpass that velocity by 150 fps. I'm loading my 375 H&H Ackley Improved (aka., 375 Weatherby) with a 300 FS at 2930 fps, 26.5" barrel. Finally, I recommend the 375 H&H Ackley Improved over the 375 Weatherby. It's slighly more case capacity, and it shoots 375 H&H and 375 Weatherby fine. Dies are readily available from multiple sources and Weatherbys are typically chambered with way too much freebore. Too much freebore can diminish accuracy and prevent using slow burning powders effectively, and the slow burners will give you more performance at lower max PSIs. AIU