It's a no win situation from what you've told us. You don't want to confront them. You don't want to report them. And they don't seem inclined to change. If it's that much of a pain I'd suggest moving on. Find a new spot. You're letting two yahoos ruin your hunting and dominate your life. If they were in the pen at sometime, it's quite possible they're not even suppose to be near a firearm. Move on.
Don't sound like an idiot with that post Dave.
Theyve either threatened or carried through with threats on several people in our area (including property damage and physical threats). I have a wife.....a child....and these guys (grandad and dad) are former residents of the state I live in (ifyaknowwhatimean).
Sounds like your not the only one afraid of them. Guess they'll do what they want when they want.