Can you make .257 weatherby brass from 7mm rem mag and how many proceudures does it take. I read here that you can and it makes good brass and can last longer than norma ??

Pretty much a run in your 257 die load and fireform. Neck will be a little shorter than factory 257 but no big deal.

As to Norma brass only time I've found it to have a shorter life was when I really tried to push the pressure. Staying at 65,000 or less I've never had a problem. Yes some of the other brass on the market will handle higher pressure.

I just lube the 7mm brass well and run it through my .257 Wby Mag FL sizing die in one slow, smooth stroke. As ramrod340 states, the neck (and case length) will be a bit shorter than the .257 case.

I worked up new loads for these cases, starting with a slightly lower starting charge. I found that I require a slightly lighter charge of powder to achieve the same velocity as with the .257 cases. This is because the reformed 7mm Rem Mag brass has slightly lower volume than .257 cases.

How easy to form .257 Weatherby from 7mm Weatherby brass? The local gunshop has stacks of 7mm Weatherby brass, nothing in .257 Weatherby. Unless I want to spend close to $100.00 NZ on 20 rounds of the stuff - no thanks!

Michael.

quote:

How easy to form .257 Weatherby from 7mm Weatherby brass

To be honest I have never tried to neck down a Wby radius shoulder. Just looking at the deminsions the shoulder would need to move back a little and the neck trimmed.

kiwiwildcat

is so easy as to FL size de 7 wby cas with a 257 wby die

is the same case

I had do it for years

good luck

When I necked 7mm Rem Mag down to 257 Wby it was .05" too short in the neck. FYI.

LWD

PC,
I own a 7mm Weatherby. There was a time when Weatherby brass was not readily available. The rifle shoots well and I used it extensively on animal cull shoots. I used 7mm Rem. Mag. brass with absolutely no problems. The neck was a little short but the cartridge headspaces on the belt. The short neck also saved me the necessity of having to trim the brass.

Use a good spray on lube and it's a one stroke process with the FLS die to get the nice double radius shoulder. I was finally able to pick up a supply of Weatherby unprimed brass but have never bothered to use them as the reformed 7mm Rem. Mag. works so well and is extremely plentiful, usually at no cost.

Geoff

Thnaks Folks

O.K. You are going from .284 to .257. Cases are too close to the same length to worry about. Should be able to do this in one pass, but.

I have known several that just shoved .308 (7.62mm) surplus cases into a .243 die and got a .243 case. Many have crushed necks too.

Some would have you run the case into the seating die first for a prelim. You could use an intermediate die. .264 Winchester comes to mind. Last pass would be the .257 Weatherby full length die.

Good lube is vital. Lee is very good. Lanolin is the old standby. (Gramps called it wool fat 'cause it was washed out of sheeps wool. Naw no sheep down under are there?) Imperial die wax is unbelievable. Castor oil works too.

AND you will be work hardening your neck. This will shorten case life unless you anneal. There are many ways. Propane torch in a dim lit room works o.k. Stand case in water, preferrably without primer in pocket, then head cannot get over 212, boiling water, temp. Heat neck to dim, dim pink/red and knock over to anneal. [Yes, opposite to steel.]

Or you can dip in molten pure lead. Hold the rim by your fingers and when it gets hot --VERY FAST-- drop into water. Alloys are not hot enough. Best is 650 approx. F. This gets you around 615 F. Need to do it a little more often, but what the hey...

And the variety of 7 Rem Mag cases is endless. Very popular. Many brands. I guess there are some military snipers using it. No idea about NZ but up here, lots of fired cases cheap. luck.