I was able to do the Valentine's Day duty and fit in a trip to the range yesterday. It was a perfect "blue bird day," as a duck hunter would say. Calm and sunny and temps were 39 to 40 degrees F from start to end of shooting, finished about 90 minutes before sunset..
I have found a load to try at "shooting the diff" between 400-grainer and 403-grainer at 600 yards. This is with W-W brass having 94.4 grains gross H2O last time I checked:
80.0 grains of loose pour was about 100% LR at 3.480" COL with the Shock Hammer "404/.458." 81.0 grains with drop tube might be more efficient at 3.480" COL with the Shock Hammer in the W-W brass.
By comparison, the Hornady brass was 94.3 grains gross H2O and should be interchangeable for load data.
My lot of Norma brass is bigger at 98.8 grains H2O gross when checked same way as the W-W and Hornady methods.
To simplify and round to nearest grain of H20, when all brass is 2.500" long, 95 grains for W-W and Hornady 99 grains for Norma, my lot. The Norma manual claims 95 grains for their brass but might be for new, unfired, and shorter than 2.500" and/or might be a variation in lots over the years. I go by once-fired, not sized, and full 2.500" for my 95-grain simplification with the W-W and Hornady. BTW, that is the default case capacity assigned to the .458 WM by my QuickLOAD software, an old version. Discussion of R-P and Federal brass will be saved for later attempts at tedium along with the making of .458 WinMag brass from any belted case long enough, especially the .458 Lott. Heh heh.
Norma brass, same rifle, 39*F at start, 40*F at finish, all with "404"/.458, F-215, AA-2230
3.380" COL 78.0 gr >>> 2395 fps MV 80.0 gr >>> 2489 fps MV
3.480" COL 80.0 gr >>> 2425 fps MV 82.0 gr >>> 2496 fps MV 84.0 gr >>> 2545 fps MV
Compare to
Hornady Brass 3.480" COL 80.0 gr >>> 2479 fps MV at 48*F
W-W Brass 3.480" COL 80.0 gr >>> 2475 fps MV at 39*F 81.0 gr >>> 2517 fps MV at 39*F, charged with drop tube
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.