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To start, 10gn of H110 with a 240 SMK @ 2.260" is about 75% case capacity.
H110 is designed first and foremost as a magnum pistol powder and works best with a heavy roll crimp. This allows for a fairly high pressure build before bullet release.
When used in a .300/WTF there isn't much for neck tension and it can be erratic based on the cases and how they were formed (.221 expanded or varying 5.56mm trimmed) this in turn makes them very prone to being temp and position sensitive. If at all possible adjust the bullet seating to balance with powder charge to be between 90-100% case capacity.
9.4gn of H110 with a 240 SMK @ 2.095" is about 95% case capacity. You can fine tune the exact powder/ COL length once you're in the ballpark.
If you want to go the extra mile you can measure neck thickness and once the cases are fire formed, trimmed and neck turned...anneal them.
The other options are of course to move to IMR 4227 or AA1680.
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