I think the type of cannon is ready/ mehr gibt mein Können nicht her
Welche Farben haben diese Waffen? Grau? Aluminium? Schwarz? Oder ganz anders?
What colors are these weapons? Gray? Aluminum? Black? Or completely different?
The Browning caliber 50 is very dark grey / black like the other handguns. The shielded mount should be a more metallic dark grey. From the pictures it looks like a dark brushed aluminum. I would start with dark washes and tone everything down, then add some metallic dry-brushing.