didn't I see the line that said "shooting into an occuppied dwelling"..??
I see that as what probably got these guys busted, and since they were, the other charges were loaded on, (because the govt could) to add pressure to the case. I don't think they were busted for paramiliatry training, but it was added in because what they did showed their intent, and that, under the law, made the training a crime, due to the intent.
I could,of course, be wrong...
All else being equal (and it almost never is) bigger bullets tend to work better.