I will be watching for the results of the 460 NE bullets with Black Mag'3. I have been using the powder but the heaviest bullet I have shot with it to date is 300gr. I would recommend that you start fairly low in powder grains as my 300gr. SST bullet with 90gr. of black Mag'3 punched completely through an elk at about 100 yards. 100gr. of Black Mag with the same bullet hit 2000fps. over my chronograph. If I was going to shoot the heavy bullets I think I would start at about 75 or 80 grains. You are going to love this powder, especially with the heavier bullets as the performance is better with heavier bullets and it is unbeliveable for clean shooting.