.300 rum brass

[Jscb1b]

Can .300 rum brass be made by neck sizing or fire forming other brass?

 

[Steel head]

7mm rum and 338 edge

 

[Jscb1b]

What does it take to use 7 mm rum? Just running it through a .300 rum die?

 

[Jscb1b]

Never mind. Three other forums said run them through a full length sizing die.

 

[Steel head]

Yep
Neck up 7rum
Neck down 338 edge and possibly turn necks

338 rum is a slightly shorter case.
I’ve had pretty good success finding 338 edge brass lately.

 

[Jscb1b]

With the .338 edge having a shorter case, does it effect headspace?

 

[Steel head]

With the .338 edge having a shorter case, does it effect headspace?

338 edge isn’t shorter, 338 rum is.
338 edge is basically 338/300 RUM
The edge, 375, 300 and 7mm rum all use the same go gauge.

 

[Jscb1b]

Thank you. Brain fart.