Can some of you .375 Weatherby shooters please give me some real world velocities with 260 gr 270gr and 300 gr loads.

I am seriously considering buying a M-70 Alaskan with a 25" tube and reaming it to Weatherby. Just trying to get some real world numbers before I drop the coin.

Thanks.

300 grainer @ 2800 fps with factory loads in 26" barrel or
2740 fps with factory loads in the 24" barrel.
That is real with 300-grain Nosler partition factory loads.
I have personally verified it.
Been hunting with and playing with the .375 Weatherby for over 25 years.
That is real.
And it is not hard to duplicate with handloads using H4350.
Just quit when you get to the desired velocity.
Factory loads with 300-grain Nosler partition use about 88.5 grains of something that looks like MRP.
Start with 85 grains of H4350 and 300-grain Nosler partition, and work up, with F-215 Primer.
BUT YOU MUST USE THE NORMA MADE .375 WEATHERBY BRASS WITH PROPER HEADSTAMP.
It has greater case capacity. Works great.
Max brass length is 2.860", trim to 2.850".
This is 0.010" longer than .375 H&H.
If you just fire-form .375 H&H brass, you are going to be way short on the brass length.
REPEAT: USE PROPERLY HEADSTAMPED BRASS MADE BY NORMA.

The .375 Weatherby was the first ever .375 H&H improved, back in 1947.
It is still the best of the lot.
Be sure to specify the latest CIP specs for the .375 Weatherby reamer.
Weatherby shortened the free-bore to perfection in 2001.
CIP adopted that spec thereafter.

Improvement:

The heavier the bullet, the better the advantage of the .375 Weatherby over the .375 H&H, all operating at the same pressure:

Up to
270-grainers: +150 fps.
300-grainers: +200 fps
350-grainers: +250 fps.

This is true.

Real world velocities vary a little from one barrel to the next, and one load to the next, but on an average I would say mine increased velocities over the 375 H&H by at least 150 fps.

2850 with nosler 260 AB can get 3000 but at 2850 it shoots real good
2800 with factory 300 nosler partion

I have a Rem XCR II rechambered from 375 H&H to 375 Weatherby with a 24" barrel. 375 Weatherby factory 300g Partitions clocked in just over 2700 fps. I've been too lazy to reload for it yet, but I have a bunch of 350g Woodleighs on the bench staring at me.

quote:

USE PROPERLY HEADSTAMPED BRASS MADE BY NORMA.

Good to know thanks!

I should add that my 375 wby has a 26 inch shilen barrel on a winchester m70 crf action

I got 250-grainers @ 2825 fps to 350-grainers @ 2400 fps. 300-grainers I run @ 2550 fps and 260-grain Accubond @ 2700 fps. Accuracy over speed...