Just purchased a Model 70 in this 338 wm wildcat and can't find ballistics or reloading data. Any help is appreciated.

Also, if anybody knows anything about the development of this cartridge, that would be equally appreciated

Thanks

For all intents and purposes, a .338 Winny necked to 7mm (0.284") = 7mm Rem Mag

Yep unless they changed something other than necking it down it is a 7mag. YEARS ago saw some 7-338 wildcats. Some called 7-338 others had something else in the title. Since the 338 is about 4 years older than the 7mag I ASSUME these were made prior to the 7mag. But who knows.

It's not exactly a 7 mag. The shoulder is more open then the 7 mag, resulting in increased case capacity (about 10 grains according to the previous owner)

I presume you have fired cases?

Just compare volume with a 7mm Rem Mag.

If you are in the 5-10% greater capacity you can either adjust 7mm Rem Mag data upward proportionly, or . . .

Find and use 7mm Dakota data. It's 8% greater than a 7 RM. There are a few current load manuals that give data for the Dakota. IIRC - Nosler #6 does.

Good luck, have fun and be safe!

Doing a web search it comes up several times but always as a 338 necked down to 7mm. Never a mention of blowing it out moving the shoulder etc.

Like Muskegman said take one of your cases and measure the water capacity to the top of the neck. Full case. Compare that to a 7mag. I show a 7 mag as 80.8+/- if it 10 grs higher then you are real darn close to 7mmDakota. If not calculate how much larger you are.

If your case is 10% larger then a starting point is taking 7mag data and increasing it by 10%. Start LOW and work up.

Thanks