7 mm mag ?

[ann brezinski]

a friend is building a 7 mm magnum on the 300 Winchester case.our ? is given 160 to 180 grain bullets and a 26 in barrel how much faster will it be over a 7 mm Remington.all so what would you use for powder and find load data?
gary b

 

[MudRunner2005]

a friend is building a 7 mm magnum on the 300 Winchester case.our ? is given 160 to 180 grain bullets and a 26 in barrel how much faster will it be over a 7 mm Remington.all so what would you use for powder and find load data?
gary b

7mm x 300 WinMag... It is a wildcat cartridge. There is not going to be any professional published load data anywhere, that I am aware of.

Where to find load data? Try reloader's nest, or read through this thread... http://www.longrangehunting.com/forums/f19/anyone-own-7mm-300-win-mag-51404/

As for powders... IMR 7828, 7977, H1000, RL25, RL33, any of those will work.

As for velocities, it should be somewhere in between a 7mm RemMag and a 7mm STW.

 

[Garycrow]

Google 7mm Mashburn. It's a round that's been around for quite a while and was originally made from shortened 300 H&H cases. Now everybody makes them from 300 win mag cases because it's just a simple neck down to 7mm. It is for all practical purposes a 7mm-300 win mag, your friend's cartridge will be basically identical to it.

That's where I'd start for load data. From what I've read you can expect about 150 fps more than a comparable 7mm rem mag, usually about 3200-3250 with a 160 gr. bullet. It's about halfway between a 7mm rem mag and a 7mm STW.

 

[Frank in the Laurels]

Why ??? Just do the 28 nosler or 7 rum and not worry about it, people !!!