B & R Photography

The quarter bore with a whole lot of horsepower or in this case gun-powder. The .257 Weatherby Magnum was one of the first Weatherby cartridges introduced to the commercial market. This cartridge was based on the .375 H&H Magnum necked down and the shoulder blown out.

Originally the cartridge was only available as brass components until 1948 when Weatherby began to offer loaded ammunition for it. It is said that the .257 Weatherby Magnum was one of Roy Weatherby’s favorite cartridges.

The cartridge is known to be flat shooting with good long-range performance. The downside at the time was the projectiles as they had lower ballistic coefficients which made them shed both energy and velocity allot quicker than other calibers.

This cartridge is a hunting round. As of this date no known shooting discipline has adopted the cartridge to its sport. However, being a flat shooting quarter bore this cartridge lends itself to being very good for things like Prairies and Mountain terrain where medium game and smaller animals are expected to be hunting. This would include things like pronghorn, deer species, mountain goes and mountain sheep.

The cartridge is also fantastic for predators and predator management. Used on animals such as the cougar, bobcat, lynx, coyote, fox and wolverine. While you could use it on varmints the recoil and cost per round really makes it not worth the effort.

One more thing to mention before I get into the ballistics is that this cartridge is considered overbore. So the barrel life tends not to be very long.

As far as trajectory goes the .257 Weatherby Magnum loaded with a 100gr Barnes TXS produces a velocity of 3570 fps at the muzzle with 2829 ft-lbs of energy. When zeroed at 100 yards you get the following bullet drop:

200 Yards: 1.72 inches of drop.

500 Yards: 32.18 inches of drop.

1000 Yards: 231.05 inches of drop.

(Please note the above trajectory information was pulled from https://gundata.org/blog/post/30-06-ballistics-chart/)

This cartridge does quite the job when it comes to ballistics but as mentioned earlier does suffer from projectile choice. However in recent years the quarter bores have started to see a comeback so I would be interested in see what some new projectiles would do for this cartridge.

Short Notes.

Official Name: .257 Weatherby Magnum.

Year Designed: 1944.

Designed by: Roy Weatherby.

Parent Case: .375H&H Magnum. (Technically it was originally designed based on the H&H Super 30.)

Rifling Twist Rate: 1 in 10”. (1 in 12” were used originally.)

Maximum Point-Blank Range: 350 Yards. (When using the 100gr Barnes TSX loading.)

I hope you enjoyed this brief overview of the .257 Weatherby Magnum and will return next week for our Cartridge of the Week series.

Please remember to always practice safe muzzle control when dealing with firearms and happy shooting.

B