Necking down magnum basic brass

[analog_peninsula]

Hi everyone,

I bought some magnum basic brass for a .375 wildcat very similar to the.375 Weatherby that I’d like to take to Africa. What’s the best way to reliably neck down the cylinder brass very similar to Lott brass in dimension to .375 caliber?

Hints, tips, and suggestions are greatly welcomed.

 

[Ray B]

the inside diameter of cylinder brass is about .47" so necking it down is reducing the diameter .05" around the circumference. this would best be accomplished in two stages. One die would reduce from .47 to .42, then another from .42 to .37". A sizing die for a cartridge such as .404 Jeffery would probably work for the first step since it has the two necessary features: the open end is large enough to accept the unsized brass and has a very gradual sizing down to .42". the only question for that first stage would be if the case is long enough to get into the sizing portion of the die to get the case reduced to .42". the final sizing die may be the actual cartridge sizing die, the issue is if the shoulder angle is flat enough that it can reduce the neck diameter without collapsing the case. If not, then another die, possibly a 375 H&H would work to size the case. the problem with that is you would want to push the case into the die just enough to reduce the top of the neck to .37 as the body of the case would be reduced more than you'd want and would be needed to be fire formed out to the wildcat's dimensions.

 

[lkydvl]

WHY NOT JUST FIREFORM IT FROM 375 H&H?

 

[BlueFlyer]

Per the advice above, but anneal the brass before and after forming.

 

[analog_peninsula]

WHY NOT JUST FIREFORM IT FROM 375 H&H?

This is international travel brass. Incorrect head stamp.