Home Forums Hunting & Shooting Express Rifles and Big Bores Only The great 458 Winchester. Everyone should own one at least once

Sir Jerry,
Sad but true and ironic as hell !

New data on pressures coming in, hopefully will have it on your buffalo load before you go.
Off to a good start:











Old AA-2230 powder data showed a surprising drop in pressure for merely going from 3.28" COL to 3.38" COL.
Stay tuned for more on that.

Recommended load of 75 grains AA-2230 (new vintage) with CEB 450-grain safari Solid:
.458 Winchester Magnum, standard SAAMI chamber and loading constraints
Winchester M70 Classic factory barrel shortened to 20"
Winchester brass
F215 Match primer (GM215M)
3.282" COL
55,600 psi (strain gage)
2226 fps MV (LabRadar)

That would give about 2300 fps flat MV in a 24" .458 WinMag.
An elephant could not tell whether your barrel was 20" or 24" with that load.

I say increase the COL to 3.380" and increase the powder charge until the elephant notices a difference.