257 Weatherby Magnum

A mate has asked me to help set up reloads for one.

I'm looking for any tips or advice for this cartridge because I haven't reloaded for a belted magnum before.

Attachment 143755

I understand that the first thing is to set up the sizing die close top the length of the fired case so you only bump the shoulder back .003" approx. (same as all cartridges). The Weatherby doesn't seem to have an official datum on the shoulder, just specs for the end of the case body and the start of the neck. Would it be OK if I just use my 0.400" collar and use a length from case base to that ? Or does it have to be .3963" x 2.117- ? I see the chamber spec uses a 0.4050" diameter.

I think the rifle is a Weatherby Mark V .
I'll be using a co-ax press and Redding dies.
I'm used to loading for 7mm08 and .303.

I haven't got a Weatherby case holder for priming so might just have to use the priming facility on the press ?

I'll ask more questions but first see what comes back for those two.

What else should I look out for ?

Many thanks in advance.

What Projectiles are you considering ?

I haven't checked but I think its relative obscurity as a cartridge would make factory ammo scarce and expensive

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Originally Posted by stevodog

I haven't checked but I think its relative obscurity as a cartridge would make factory ammo scarce and expensive

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Yup. Doubt there would be much around to pick from.

Quote:

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Originally Posted by stevodog

I haven't checked but I think its relative obscurity as a cartridge would make factory ammo scarce and expensive

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A few years ago I ordered some factory ammo for the above calibre from Hunting and Fishing. I don't think the fella who I spoke to knew much about it, or anything really and verbally indicated it would be expensive-around $180 for two boxes. When it finally arrived a couple of months later I had to pay about $350 for the two boxes!

On a positive note, it was this that encouraged me to getting into reloading. As yet, however, I haven't needed to load for it as its not my main rifle. Will follow the thread with interest.

@gregdudehunter

Sent from my ELE-L09 using Tapatalk

Looking at the headspacing, most cartridges have a length of conical shoulder so that measuring to say .400" diameter will define the headspace dimension quite well. But the Weatherby have two circular radius edges and hardly any shoulder, which is almost flat. So perhaps measuring headspace with a .400" hole might be quite insensitive, varying substantially from one case to another. Would I be better to try and get the guage onto one of the curvy radius parts and are they even similar shapes between rifles ?

Here's a picture comparing the shape of the 257 Weatherby to .308 win and 7mm Rem Mag.
(just copied and stretched from the wikipedia pages, showing shape not exact size).
Attachment 144415

Thanks - use your own chamber as the headspace reference and not make up a nominal inch value to aim for ?
Do you mean the neck or the shoulder ?

Bagheera, get hold of the rifle from your mate if possible and as you adjust the die down, check the case in the chamber. Keep going until the bolt close meets little/no resistance. I like to cycle the used brass and find the "stickiest" i.e. most expanded case in the batch to work with, assuming this will be the best indicator and not give a false positive so to speak. Apologies if i'm telling you how to suck eggs :).

Also,

https://www.guncity.com/hornady-257-...3330fps-309470

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Originally Posted by csmiffy

Yup. Doubt there would be much around to pick from.

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hornady precison hunter ELDX