Don't be afraid to shoot it. Good news is the M8 is the "easiest" to get spares for. Biggest thing is DON'T use a harsh brush on the gas piston. You will erode the rings using a steel or even a brass brush. It's doesn't need to be inspection clean. Use your favorite solvent and let it soak and wipe off the excess carbon fouling. Here is a video from probably the preeminent HK armorer talking about this.A P7M8 was a grail gun for me. Luckily, I found a fellow INGO member a few years back that made me a decent deal on one. I would never carry it and rarely shoot it just because of the scarcity of parts.