I've shot my Caldwell three times now. Every time it seems it has to be with a bigger bore, heavy slug so it does some pretty good damage. The first time was the best one. Shot through close to the top of the faceplate, making shrapnel plastic bits of the inside, ricocheting down to blow the battery and cover out of the bottom. Removing the broken pieces, I discovered a random capacitor in the bottom that I could not find where it came off the board at. So I rewired the battery terminal and it worked just fine. Since then I have got couple of good "skips" off the top also that did some good gouging and cracking. I did buy a "spare" that is a few percent lower in speed, but it hasn't been needed, yet.