A wheel I made to help keep track of gunnery numbers in BattleTech and avoid having to look at the reference sheets.
Positions on the top part represent what the attacker did that turn. Staying stationary is the blank in front of 'Walked'. This is aligned with the tabs on the lower part representing how far the target moved in that turn.
The three open spaces represent short, medium and long ranges and give the target numbers for clears shots, up to +3. One of the supplied pictures is where both attacker and defender stood still, the other is where the attacker ran and the defender moved 3-4 hexes (or the attacker walked and the defender moved 5-6).
This only works exactly with the BattleTech default gunnery score of 4+ but it's a glorified counter. Rotating the wheel a position right or left will also increase or decrease the given numbers, respectively, by one. In our games, we've found it quick and easy to use these to calculate a standard shot, then mentally correct for difference in gunnery skill.
Works best printed with white plastic and then running a pencil in the grooves to darken them. My attempts with paint haven't worked out well.