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

We are awaiting more pressure data on a 20"-barreled .458 WinMag from MIB Laboratory.
Some people like them short.

Good to know you only lose about 72 fps in chopping from 24" to 20".
That means 2500 fps in a 24" becomes 2428 fps in a 20" with a low pressure 404-gr Shock Hammer at COL of 3.380" (Norma brass if WW/Hornady/RP too hot ?).
That means 2349 fps in a 24" becomes 2277 fps in a 20" with a sub-59,000 psi 450-gr CEB brass FN at COL of 3.360" (WW/Hornady/RP brass: All good).

I SWAG that is about the velocity and pressure Doc M of MIB will find if he tests the CEB with two bands out of case, with post-2016 vintage AA-2230,
F215 primer, and WW-Super, Hornady, or RP brass.
WLRM primers will do fine, they are very close to F215 and the same-same GM215M.

Still waiting for Pac-Nor to send a 10"-twist barrel for 24" length for an FN Mauser 98 .458 WinMag.
That will be tried for comparison (by me) against a Pac-Nor 1:10" barrel of 19.75" length on the .458 B&MW Winchester M70.
Those two cartridges have same throat and have same case capacity when COL is adjusted properly with the specified bullet.

That fast twist will allow the long and pointy VLD bullets to be tested at supersonic speed,
and all sorts of shorter bullets to be tested at subsonic speed.
And the 24" Mauser will be threaded for suppressor.
The Vietnam fiasco of the suppressed .458 WM-1.6"&1.3" with 500-gr FMJ at 1100 fps can be improved upon, no doubt.