u/ImmediateCancel7374

I have a S&W Sport 3 with a Kabuto mini and 3 stage selector that I got from a trade that Ran fine in the third position for a few weeks and now nothing but one round and a light strike and dead trigger . The BCG is a BCM . When I dry fire and hold the trigger in, the bcg/ charging handle is super hard to pull back around the halfway point. Any ideas or advice as I’m still fairly new to the ar platform and would really appreciate it.