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

gunner500,

Well then, I know you are a master caster and BPCR shooter rivaling your mentor Bill "sharpsguy" Bagwell.
(Let us not mention how much better you are at +1000 yards with your scoped .338/.378 WBY with that new-fangled smokeless powder,
so as to maintain respect for our elders.)

Have you tried the powder-coated, gas-checked bullets yet ?
I bet the start pressure and bearing surface of a PC-painted FNGC from the proper mould would be closer to the TBSH 500-grainer
than the Ol' Hornadys.
The drill for smokeless, high-velocity loads in the .458 WM+ is to size those high-tech, homemade bullets
(PC-painted, and gas-checked)
to 2-thou greater than your groove diameter,
and make them out of hard alloy about 25 BHN.
Different from your buffalo-butter-piercers with BP.

Here is how H4895 (compressed) and AA-2460 (non-compressed) compared with my homemade 543-grain FNGC-PCP:



Subtract 15 fps from my 25"-barreled chrono velocity at 5 yards to get corresponding 24"-barrel result,
if JES barrels are comparable to Shilen.
Some guys say their 18.5" custom barrels shoot faster than their 22" Winchester factory barrels, however !



About 2200 fps MV seems to be the accuracy limit on MV with the BHN 25 FNGC-PCP.
I now have a bee in my own bonnet buzzing about a hardcast 500-grain FNGC-PCP seated to 0.350" depth to mimic TBSH loads.