8mm RM brass to 7STW ?

[RH300UM]

300 bee = 97.5 gr. H2O in Weatherby brass 3x fired
300 WM = 94gr H2O in Winchester brass 2x fired

according to my reference books, volume of weatherby 300mag = 137gr H2O ; Winchester 300mag = 116gr H2O

 

[brewster29]

Got my hands on some 8mm RM brass . To make it 7STW is it as simple as lubing it and running it through a full length sizing die, or are there other steps ? Need a little advice from someone with experience . Thanks in advance.

That's exactly what Laine Simpson did back in the late eighties to get the 7 STW started. That's also what us old timers had to do until 7 STW brass became readily available. It's an easy operation and I never lost a case doing a couple hundred of them.

 

[Tidesloe]

Many of you guys probably already know, but ADG will be producing 7STW brass this year. It will likely not be easy to get initially, but there will be quite a demand for it.
I've never necked down from 8mm, but I'd probably step the neck down a time or two before running it through an Fl die, then run the correct size mandrel in it and then neck turn.
I would definitely anneal maybe a couple of times through that process. That's a lot of work on the brass. Just my thoughts on it

 

[Jim’s Hunt]

I like all of this neckiofown stuff

 

[Jim’s Hunt]

I like all of this neckiofown stuff

This was not meant to be sent. I wanted to say I love this necking down stuff but by all means get some Redding imperial die wax. It will make the job a little easier

 

[dogz]

That's exactly what Laine Simpson did back in the late eighties to get the 7 STW started. That's also what us old timers had to do until 7 STW brass became readily available. It's an easy operation and I never lost a case doing a couple hundred of them.

Correct, we also made 340 Wby brass out of 8 RM as well

 

[WapitiBob]

I'd just buy some of the available Nosler brass and not fiddle with necking down.

 

[brewster29]

Except then you have Nosler brass. I have been very unimpressed with the stuff I have used.

 

[Tidesloe]

Nosler brass is ok, if your not stepping on it too hard, but ADG coming out with it this year will breathe new life and interest in this great cartridge.
Necked down 8mm would probably be better brass than Nosler though