There Sir Jerry goes again, talkin' way over my header. Drag racing lingo of which I am ignorant. Oh well, I'll stick to busting rocks and such. Speaking of which ...
Remember that a .458 B&M+ with COL of 3.220" with the 404-gr Hammer has same case capacity as a .458 WM+ with COL of 3.480" with same bullet. So this is like Sir Jerry's Safari load. The 16.9" barrel makes it about 150 fps slower at the muzzle than a 24" barrel. The shorter and fatter .458 B&M case is possibly more efficient than the longer and skinnier cases, especially the .458 Lott, heh-heh.
Ron aka "Rip" for Riflecrank Internationale Permanente NRA Life Benefactor and Beneficiary .458 Winchester Magnum, Magnanimous in Victory THE WALKING DEAD does so remind me of Democrap voters. Donkeypox.