An automatic sentry machine gun turret presented at Russian "International military-technical forum 'Army-2021'" couple of days ago. Yes, that's a Maxim. : r/ForgottenWeapons
ArtStation - Sentry gun
Automatic Sentry Gun Weapon Free 3d Model - .Max, .Obj, .Vray - Open3dModel
Killer robots: The soldiers that never sleep - BBC Future
USCM Sentry Guns - Prodos Games
Sentry Gun - Official TF2 Wiki | Official Team Fortress Wiki
Sentry gun - Wikipedia
Portal Automated Sentry Gun by SWAT-Strachan on DeviantArt
D.I.Y. Scrap Metal Auto-Turret (RaspberryPi Auto-Tracking Airsoft Sentry?!) - YouTube
Are automatic turrets and sentry guns real? - Quora
Samsung reveals SGR-1 robot sentry set to keep an eye on North Korea | Daily Mail Online
STL file UA 571-C Sentry Gun - Aliens・3D printer model to download・Cults