Dust shooting bank...
All it cost is some time behind the rake...
That system has been around since the invention of the rifle,,, 2 to 400 ish +++ years if I recall...
The next system costs a few bucks,,, iron gong with gasoline engine knock sensor,,, $7 if I recall...
Mount on back side of gong... The vibration will trip the sensor,,, hook the out put feed wires to a coloured light of your choosing,,, $5...
Life dosen't get any simpler then that you know...
Saved funds can go towards a few new rifles or shooting supplies...
I use the dust bank system since mother nature corrects it everyday,,, no rake required at our shooting spot.
100 to infinity is gooder