This instructable will show you how to make the combine turrets from Half-Life 2. This design took a long time to make, and I hope it meets satisfaction! (By the way, the pictures were taken at night, so some of them might look a bit grainy, and the lighting may look a bit rough.)
I think I will improve the design later, but right now, this is all I’ve got.

Supplies

See picture

Step 1: Main Active Zone

This is where the computer, magazine and barrel are installed (aka the dangerous bit). Also, the light grey piece is actually a bracket used for attaching bricks to the back of minifigures, so if you can’t find one in your regular Lego supply, check your collection of minifigures. The one it is usually seen on was Emmet from the Lego Movie sets.