I’m not sure I need to discuss the utility of having a really good rendition of the German Mk 103 cannon available in this scale. It was used on a number of aircraft - slung under the wings of tank-destroying Fw190s and Hs129s, mounted in the Do335 and the Horton Flying Wing, and even used in a fair number of ground mounts. This 30mm weapon was not to be trifled with.
It is, however, a fairly difficult shape to successfully mold using the standard styrene molding processes. Master from Poland has come to the rescue with a lovely little kit from their Air Master series. The kit supplies two complete barrel assemblies, including the barrels and adapters in brass and two variants of the complex gun muzzles in resin.