Last spring I was getting several guns ready for a Pistol Caliber Carbine / Subgun class. After doing a bit of research and needing at least 2 RDS for the guns I was going to take, I finally settled on Holosun HS503GU. Uses readily available CR2032 batteries, like 50,000 hr life on low setting, Auto off with shake awake to extend battery life and biggest advantage for PCC, a choice of reticles. Standard 2 MOA red dot or my favorite 2 MOA dot surrounded by a 65 MOA red circle. The combo reticle was perfect for it's use. The 65 MOA circle was great for CQB distances and house clearing and the 2 MOA dot provided the needed accurate aiming point for 100yd+ shots or hostage taker elimination shots to the sweet spot. There was plenty of brightness adjustment to keep the sight easily visible in the brightest sunshine that I encountered. Temperatures were not extreme, mid to high 80's but the second day it poured rain in the morning and the temp/humidity climbed through the afternoon. No evidence of fogging whatever. The HS503GU handled the recoil of my full auto HK MP5 through roughly 1200rds in 2 days with out any loss of zero and the gun/sight combo got banged around a bit. Also the low mount worked perfectly to co-witness with my MP5 sights and with the factory fixed sights of my backup CZ Scorpion Braced Pistol. Liked the performance so well, that I bought a third HS503GU for my new CZ Scorpion Micro.
Now the bad news, apparently Holosun has discontinued the HS503GU, although there are a few still available on Amazon and I may pick up another before I run through the PCC/Subgun course again this summer. I need one for my 9mm Colt AR Carbine.
