This is a 3d printable model of a 4 barrel cannon design.
Desinged using Fusion 360.Initialy designed for mounting on the back of an RC car you will find it may be rather large but will scale down nicely in 3D sling software.
The over all sizes are.H 11.586mm from the bottom of the base to the top of the gunL 267.15 mm from the tip of the barrel to the back of the gun (not base plate)W 79.039 mm thats the widest part which is the base width