300 weatherby to 338 WM

[sealer]

I have 60 pieces of 300 Weatherby brass that I will reform to 338 WM if nobody trades me out of them.
What will be the easiest way to reform this brass with the tools that I have ? I have 7mm RM, 300 WM, 338WM die sets and I have a case trimmer also, but no outside neck turning attachment. I also know how to anneal.
TIA, Dennis

[MarkP]

You will most likely need to hit the double radius shoulder with the 338 die such that the cartridge will just chamber in your rifle. Trim to max length and fire form, measure length and adjust trim length to obtain proper length.

I have a 300 Wby and have formed 340's in one pass using a Hornady elliptical expander ball.

[Duckiller]

You sure you want to do this? Per my Barnes manual head dia for Weatherby is 0.5315" for Win is 0,532". At some time in the process you are going to have to trim off the original neck on the Weatherby, 0.325 " . Without checking dimension I once tried to reform a 300 Win Mag into a 338 WM. Crusher it and made a mess. I also have done thing that don't make sense for the time spent vs money saved. We have a fun hobby. Have fun and good luck.

[ulav8r]

You sure you want to do this? Per my Barnes manual head dia for Weatherby is 0.5315" for Win is 0,532". At some time in the process you are going to have to trim off the original neck on the Weatherby, 0.325 " . Without checking dimension I once tried to reform a 300 Win Mag into a 338 WM. Crusher it and made a mess. I also have done thing that don't make sense for the time spent vs money saved. We have a fun hobby. Have fun and good luck.

Read the OP. Weatherby to Weatherby, no Winchester mentioned.

[Duckiller]

WM is Weatherby not Winchester?

[ulav8r]

WM is Weatherby not Winchester?

Possibly, not definitive. I could be wrong. Too many people are too lazy to type out full names in order to eliminate any confusion. Including me at times. I have seen WM used as Weatherby Magnum and as Winchester Magnum, so there is clearly the possibility of misunderstanding, especially if the person using WM is a Weatherby fan talking to a Winchester fan, or visa-versa. I am not a fan of either, or any other magnum.

[MT Chambers]

I don't believe weatherby makes a ".338 magnum".

[MarkP]

Same head diameter both based on H&H case.

[ulav8r]

I don't believe weatherby makes a ".338 magnum".

Right, it's a 340. Still shows how incomplete/ ambiguous info can lead to a lot of extraneous off topic posts that don't answer the question, such as everything I posted in this thread.

[Duckiller]

Not sure what manual you are using. Barnes has a slightly different head diameter for for the 338 WM and 375 H&H.