Is the 340 just a necked up 300 case?

What about the 375 weatherby, can this brass be made from 300 brass?

thank you

The 340 is a necked up300 .you can make these cases real easy!! Lube the inside neck and run them through your 340 dies.that simple

Necked down, then fireformed 375 H+H cases would be much cheaper. I suppose if you start with RP 300 Wby cases, it would be push.

The Hornady belted magnum basic would work also.

LWD

quote:

The Hornady belted magnum basic would work also.

I always found necking up and down with the double radius a pain in the neck.

Maxx It is easier to make 340 Wby or 375 Wby cases from 375 H&H brass. In both cases use new brass. With the 340 start with the 340 sizer backed out a couple full turns. Start sizing the 375 brass in steps.When you have most of the neck sized down to 338 you should be able to chamber the case in a 340 chamber with some resistance just as the bolt is fully closed. Load and shoot these cases and they will fireform perfectly. With the 375 Wby simply load 375 H&H brass and fire in the 375 Wby rifle. Hope that helps

Thanks for all the info guys. I have lots of 300 weatherby once fired brass from my 300, and am looking at building a 340 at the moment.

thanks

Heck if you want a 340 and have 300 brass. Give it a try. Doesn't work then go with another approach. Wouldn't let case forming stop me if I wanted a 340Wby.