Very Low round count Custom DTech Upper with 1/10 twist Shilen fluted Stainless barrel threaded for Suppressor with thread protector.
6mmDTi caliber. This is a Wildcat off the 6.8SPC case which is a simple neck down thru a set of Hornady dies and you can size load and shoot. It does have a 30 degree shoulder but the loads shoot great while forming.
This particular upper belongs to a friend who bought another one in 1/12 and decided he doesn't need two.