I've had an 8mm rem mag for around 30 years, and in that time have tried many different loads. My go to load is the Barnes 180 gr. TSX , with a B.C. of .381, seated .055" off the lands, over 81.50 grains of IMR 4831 & a remington 9 1/2 M primer. Velocity is right @ 3300 fps, with an extreme spread in the teens. Accuracy is sub moa. A good load all in all. What keeps it from being a great load is the comparatively low B.C.
If I can accurately get this new 190 grain Swift Scirrocco with a B.C. Of .511 to 3100 fps it will add at least 200 yards of effective hunting range to the so called obsolete
8mm Remington Magnum. It may actually become competitive with the 30 cal. Magnums past 500 yards. The lack of higher B.C. Bullets is what was killing the 8 mag.