Some time ago, I was attacked by the .480 Ruger bug, and managed to acquire one of each manufacture (MRI, Ruger, Taurus) before the factories pulled the plug. At that time, CPBC touted its 410 gr. .476 bullet as ideal for the .480 Ruger. They do shoot well in my guns, but I get better groups in the SRH with a 425 grainer. The MRI-BFR prefers the Montana Bullet Works 400 grainer, while the Taurus does its best with jacketed bullets, due to the tight chambers. I use Accurate #9 with Federal Magnum pistol primers in all of my loads for this caliber.