Thanks - I just received the Thunder Beast recently and took the whole rig out for the first time a few days ago.
Zeroed at 25 yards, reset zero at 50 yards, shot groups at 50 & 100 & then ran it to 200 & 300 yards.
Golf balls at 50 & 100 yards and Tennis Balls at 200 & 300 NO Problem - It was a blast.