That really isn't that much powder considering how much slower N570 is. I normally run 68-71 grains of H1k, or 69-72 grains of Retumbo in a 7 mag with 180 bergers depending on the gun or components. Considering in my .338 Norma, n570 took 95 grains to produce the same velocity that 92 grains of retumbo did with the same bullet, and also the density of N570, his charges seem right about in line. H1k is not at all like N570, you will use much more N570 than H1k in any given chambering. About the only similarities are they should both be pretty temp stable, and they are both on the slow end of burn rate, with N570 being slower. H1k when compared to N570, produces lower velocities, burns cleaner, so less carbon fouling, burns cooler for longer barrel life, and has less case fill. N570 will generally produce about the best velocities possible in cases it works in, aside from maybe rl33, will carbon up a barrel quicker, and will erode a throat faster when ran at similar pressures. Both are very good powders that work in many of the same cartridges, just depends on what you want out of them. H1k is my preference for consistency and accuracy, N570 is my preference for top velocity.
How is bullet seating? Is the boat tail/bearing surface above the neck/shoulder junction of the case? And are you using a drop tube? I haven't tried it, but seems like it could work well as long as you can fit enough in to hit a good node.
