Sir John, Good load that one, since you are using the Norma brass that has gross water about 4 to 5 grains greater than most .458 WM brass. I SWAG your pressure is less than the SAAMI MAP of the .458 Lott, bless its heart.
I succumbed to the charms of a Ruger-Marlin 45-70 Govt yesterday.
I need another 45-70 like I need a hole in my head.