You can't have " a Drillings"----but you can have "a Drilling" (pronounced Dry-Ling) ....a German idea( and word),of course ; two shotgun barrels with a rifle barrel between,usually (but not always) on top. Formidable,but probably rather heavy to carry about all day. The rifle barrel,used with a cornet mouthpiece,would be very suitable for playing something like the "Post Horn Gallop", which I have seen & heard played by six British Marines using Short, Magazine, Lee-Enfield .303 rifles....very impressive !!