The first step towards judgement day has begun...
There are a few problems with the design:
1. Since it's immobile, one only needs to see through its flaws and find a way to outsmart it such as throwing a blanket over it or using a decoy so that it can waste its ammo.
2. If the gun jams, the robot is completely f*cked.
3. It seems only capable of taking out one human at a time. Combined groundforces can team against the sentry and blow it to smithereens in a matter of seconds.
Besides, who needs predictable sentries when unpredictable ground forces can do the job better?
Lol,what if they buy a gazzillion of them and place them all in a row,around corners,in bushes.and before they place them,they dig big huge ditchs and fill them with broken glass and cut up beer cans,and line them with field barb wire,then a fense that is electrified.
After all that,then the robots,then they have a few guards here and there that are more armed then Firefly and a squad of a few Alley Vipers. No body is gonna get past all that,and thats how Id use the robots. Lol.