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

bcelliott,

Dave Kiff, PT&G, has the reamer for a "450/348 Ack Imp" with a reamer shoulder diameter of 0.5350" (40 degrees)
as compared to his "450 Alaskan" reamer with a shoulder diameter of 0.5210" (16*32').
Those are reamer minimums.
The brass maximum for the traditional 450 Alaskan is 0.5200" (16*30') at the shoulder diameter, so only 0.001" tolerance minimum. That'll double headspace a rimmed cartridge.



The .450 Alaskan pictured at ammoguidedotcom is slightly different, mostly in length of brass (2.250") which gives it a longer neck,
and the neck is tighter and with no taper. The algorithm used there to calculate gross water capacity yields only 88.1 grains, not reality:



Greater taper feeds better, but bolt thrust reduction is a great selling point for the AI version, according to Ackley.

I will scan the improved and traditional reamer drawings and do a simple RCBS cartridge design for the PT&G AI reamer
and get it up here, later, for fun.

More fun is still awaiting wind, weather, and domestic chores getting in the way of shooting those BP loads for the .458 WM+ and .45-2.6" SWT.
I need to go to a private range so as to use the Oehler 35P at 10 yards instead of 5 yards, with a 100-yard paper target.
This is in hopes of the lube wads doing no damage to nor fooling the chrono.
Such a setup is not possible at the public range.
Will have to SWAG a 10-yard correction to MV.