To make .257 weatherby brass

[tyson22250]

To make or to buy .257 weatherby magnum brass, that is the question??? Wondering who has made .257 brass out of 7mm rem mag, .264 winchester or any other brass? How well does it work? How hard is the procedure? is it worth the savings?? Can you use 300 win mag?

 

[JD338]

You can make 257 Wby cases by running 7mm Rem Mag or 264 Win Mag brass through a 257 Wby sizer die. 300 Win Mag cases are too long and would require a lot of triming.

JD338

 

[nitis]

I tried this with mixed results.

With new brass being fired for the first time groups were really good same load 2nd load there was a difference.
I believe that the case capacity increases after fireforming that first round as I think the 7mm has a little bit of taper and the 257 wby.

Keep in mind there is then new relatively less expensive factory ammothat can be had for 30-35 bucks a box and shooters pro shop has really good prices on 257 brass

 

[Guy Miner]

Grandpa used to make it from full length .300 H&H brass - but that was back before Weatherby brass was even available. I've still got some of his old brass. It was necked-down, shortened and blown out. Grandpa was doing that back before most of today's belted magnums existed. I remember helping him with it in the shop when I was a kid. He'd let me seat the bullets. I hear other brass, particularly the 7mm Rem mag, is relatively easy to form into the .257 Wby.

Much easier though to just buy the right stuff. I just bought a couple of hundred new Norma cases for the old rifle. They're working out real well.

Regards, Guy

 

[2shaky]

When I was shooting it, I would buy Remington brass in 7mm weatherby. Then it was once through the sizer die, trim and ready to go. The cases have smaller capacity and need reduced loads by a couple grains. Saved a lot of money though.

 

[Jim1 AB]

Just make sure your neck thickness don't get to to thick. I would go for the 264 before the 7mm. Shouldn't be an issue with factory rifles. I've shot a few groups with 7mm brass out of a Ultra Lightweight and there didn't seam to be any pressure issues. Not enough to comment on if it was any good or not.

 

[FOTIS]

You got good advice here. The easiest is the 7mm rem mag method. Resize trim (if needed) fireform to perfect the venturi shoulder.