I have a Holosun 510c on my 9mm M16 upper and Holosun 507c x2s on my Uzi, Sterling, M2 Carbine, S&W 76, and MP5. I'm waiting on a MAC-10 that's at my dealer now and I've already got a Holosun 510c installed on the MAX-10/31K I have waiting for it.
Some of them are green reticles and some are...