Be very careful working up hot 10mm loads with 800X. You won't know it's too hot until it's way too hot, and you do need to weigh each charge like RickyD said. There are several much better powder choices for heavy 10mm.
I agree with this. 800X has a reputation for unexpected drastic pressure spikes. I have had some even weighing charges.
Longshot or AA#9 for top heavy loads is all you need. Throw your 800X away so you won't be tempted.
That last 50 fps is not worth it.
