So I've got almost everything together or on order for doing a 35x57R rifle I think, and looking for any information or tips and tricks that other people have on doing so. I've got a set of 35 Whelen dies inbound, I've got a .358" barrel blank, I've got 7x57R brass inbound (shoulder/neck look like they'll sit closer to where the dies will once trimmed). Obviously being a rimmed variation on the wildcat may present some issues, but it's necessary for the SMLE action I'm using so I'll worry about that as I get to it. How do people usually shorten the 35 Whelen dies for 35x57? I know being a rimmed cartridge the headspacing process won't be exactly the same as on the non rimmed wildcat, but any recommendations beyond just stopping and fitting every now and then for cutting the chamber without going too deep since the reamer is for a longer cartridge?

The relative relationship between the 7mm-08 Rem and 7x57 Mauser can be used as an interpolation base line to draw a similar comparison to the 358 Win and a .358"x57mm wildcat.

I'd be checking every possible source of information and working up slowly with loads. 8x57mm brass should be abundant. 9.3x57mm Mauser brass is also available from time to time

Mule Deer has some great formulas for determining a cartridges performance capabilities, but the water capacity needs to be measured first.

I'd keep pressures reasonable and barrel life won't be a concern.

Why would you shorten 35 Whelen dies when you can buy 9x57 dies? If you start with 8x57R brass you will gain case capacity.

Three reasons:

A) 35 Whelen dies are cheaper and more available than 9x57

B) 35 Whelen reamers are more readily available than 9x57

C) I still haven't quite decided how I'm going to ream this to cut the rim if needed as well, so the longer dies and longer neck of 7x57R give me some wiggle room to mess around with this a bit. If I use the 8x57R shoulder length like I'd prefer, I'd have 3mm excess between the end of the neck portion of the chamber and my brass.

Makes more sense now that you say you want to ream it with a 35 Whelen reamer.

Why not just build a 35-303, C&H has dies, cut the chamber with a 303 reamer and cut the neck and throat with rental tools.

I had an Epps built number 4 35-303 back in the late 1960s

Primarily to be different

I wouldn't spend $$ on 7x57R brass, I would use 444 Marlin brass and set your shoulder where you want it.

Chortle. Style points for fessing up, and at least one notch added to your looney card!

I considered that, but the 444 uses a .02" smaller rim compared to the 7x57R and thanks to the Lee Speed I already know that the 7x57R brass won't give me any ejection issues.



We're all loony here

I get the "loonyism" here but in my opinion, you're be far better off doing up a 9.3x57 on a 98 action.

Similar (non-wildcat) cartridge in a better, stronger action that will cost you less overall. Win/Win/Win!