The large AR500 plate target works like this.
Pressed over bar stock bored and illite bushing installed there is a spring between it at the shaft the target pivots on and a bolt shank that comes up from the bottom.
The cam forces the motor/drive towards the target up to the point it is reset then let's the spring push it back of the "dog""
This one is an old video but you can see what is going on.
Here you can see the bold shank that comes up from the bottom that the cam rides on (grade 8 bolt cut off).
Motor torque is transferred to the plate below and oillite rollers are on the motor bracket. One switch is closed all the time except it opens when the "reset" tab is just shy of contacting the "target" tab. The other switch is open except when the target is hit and falls.
It generally resets a lot faster because it is actually a 24v DC motor but as you can see from the video it will work off of 12v of your not in a hurry.
The deer feeder batteries are in feeders this time of year but I installed power ports in the rear when I built it so it could be powered remotely (you can see the battery to the right of my bullet trap).