This old turret has 3887 verts and 3730 tris and comes in two variations.
The first one is a static one, just one single mesh.
If you use the second variation you can move the turret-head and the barrel seperately.
This way you can animate the turret as you wish.
One 1024x1024 diffuse-map with specular in the Alphachannel and one normal-map are included.
You get them as PNGs and PSDs and you get the original .blend-file. Low poly and high poly included.