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

Sir Jerry,
I always stopped at 115 grains IMR-4350 and 2500-ish fps back in the day.
Hence never had a problem with the 460 Wby brass made by Norma.

I would have gone ahead with the 83-gr charge AA-2230 in Hornady brass at 3.565" COL,
but for my rifle being stuck shut by the 86-gr charge in Norma brass,
and the rain clouds blowing in from the southwest. Dang that Gulf of Mexico air mass !
But I will not try the 84-gr charge in the Hornady brass at 3.565" COL with the 450-gr TSX.
That charge worked nicely at 3.685" COL.
Increasing the COL from 3.565" to 3.685" effectively increases case capacity by 5.0 grains of water, exactly.
(41.66 grains of H20 for each inch of .458-cal diameter cylinder)
Thus, Hornady brass at 3.685" COL becomes 0.5 gr bigger than the Norma brass at 3.565" COL.
Hornady and W-W Super are better brass than that softer and thinner Norma in .458 WM !

Yep, from my results 83-gr charge ought to be +2450 fps at 3.565" COL in a 24" barrel, IF
compression of the powder in the Hornady or Winchester brass does not do what it did in the Norma brass.
I am liking noncompressed AA-2230 more and more.
80 grains at 3.565" COL and
84 grains at 3.685" COL, in the Hornady brass.
My Winchester brass is interchangeable with my Hornady brass in all my loading experience with the .458 WM.
Your rifle and mileage may vary.

3.565" COL makes for about .45" seating depth.
So, 3.685" COL makes for about .33" seating depth, which is plenty as Sir Bob described.
If I really gotta have +6000 ft-lbs from the 450-grainer, I might carry one in the chamber,
with the 3.6" magazine box filled with your 500-gr TBSS at +6225 ft-lbs and 3.545"COL, seating depth 0.355".
Like carrying two rifles.
One magazine repeater rifle and one single shot rifle all in same rifle.