see this is a revived old thread but,

not a big magnum guy... but own a pair of 300 Win Mags..

one bought cheap on an after season sell.. and the other was a trade to someone that just had to have a 22.250 I had...

When I do need a mag, I believe in making it a magnum...

worked this up and it functions fine in my Browning with zero issues... and the brass doesn't seem to mind, as I've loaded some cartridges 10 times with this load...

but 83 grains of H 1000 ( 300 Weatherby Data, 5 grains over 300 WM data).. with a 220 grain Sierra or Hornady round nose...

velocity is just short of 3000 fps...however you'd be surprised on how flat shooting a 220 grain RN can be at that MV....when I hit steel with it at 300 yds, the "Clang" sure gets people's attention....

a 220 grain SMP partition would be my pick for hunting big stuff with it...and actually think it is superior to a 338 Win Mag with a 250 grain Bullet...

but without the extensive experience others here can bring to the table... its just that, my opinion...but then again, I'm the one carrying my rifle... whistle