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

There were no pressure signs with any of these loads, primers were flattened no more than before they were fired.
The Norma brass had very tight primer pockets to start with.
By the time the primer was seated, it was pretty well flattened and below flush with the case head's face.
There was no cratering of the primer indentations.
There was no brass extrusion onto the case head face, no ejector slot smears or bright marks.
No stickiness of bolt lift.
The cases ejected smoothly, effortlessly, falling out of the chamber.

The Woodleigh Bullets Loading Manual singled out Benchmark from the seven propellants they tried
in the .458 Winchester Magnum: "Benchmark gives excellent results in this cartridge."
That was in reference to Woodleigh bullets from 400-gr to 550-gr.
Benchmark offers many possibilities for loading more than just the 404-gr Shock Hammer and 400-gr CEB brass FN
at various COLs and performance levels.

Benchmark is the temperature stable powder very close to burn rate of IMR-3031.
IMR-3031 was the old standby for the .458 WinMag and 500-grainers at 2150 fps from a 24" barrel.
I was doing that in the last century, before the dark age of .458 WinMag denial descended upon the world.

IMR-3031 was an old favorite for use in reduced loads with fillers in the huge Nitro Express cases.
Same could be done with Benchmark, for low velocity loads in the .458 WinMag,
from .45-70 Gov't. to beyond .458 Lott.

Bless Jack Lott's heart.
He always meant for his wildcat to be done in an existing SAAMI .458 WinMag chamber with no setback of the barrel.
After he saw what Art Alphin and SAAMI did to the .458 Lott throat, he just could not bear it.