300 WSM into 7mmWSM

[Ironworker]

I just read that Lupua will begin producing 300WSM brass. How can this be turned into 7mmWSM Brass

 

[mharp]

I did it a couple of years ago. Think I just ran it thru the 7wsm die. Extra deep to size the neck length enough to chamber. I remember cutting the shell holder down. Then straightened up with a mandrel and fire formed.

 

[46and2]

The shoulder is about .035" longer on 7wsm. I sized virgin 300wsm brass down just enough to have an .004 interface fit on the neck shoulder junction. Then neck turned after fire forming.
The case necks will be pretty short afterwards ( 7wsm has a short neck anyway) so it's not ideal but with no sources of brass I had no choice.