I think the only drilling i would want is a 20/9,3x74r/17Hmr. The shotgun barrel on top of a free floating 9,3mm barrel and the 17hmr in the middle to the right not weighting more than 2,5kg. This would satisfy my need for a drilling.

But one of those pre-war drillings where you are able to take the rifled barrel clean of the shotgun barrels, that one would serve as a shotgun also as we are at our six gun limit.