I have a Holosun 515 on the 8" and a Vortex Sparc AR on the MPX-K. I had a Vortex Prism 3x on the 8" for a few months. I had a flickering illumination problem after approx 3k rounds, sent it in for warranty repair, lasted a few range visits, then problem returned. Sent from my SM-T710 using Tapatalk