Description The K9 11.5 features a proprietary patrol-length gas system that is smoother than carbine length and more reliable than mid-length. It has an optimized gas port designed to run reliably whether suppressed or unsuppressed. The K9 continuous taper is the most effective profile for dissipating heat from heavy use. By shifting weight to the back of the barrel, modern attachments on the front help create a perfectly balanced and easier-to-handle rifle. The updated target crown, inherited from the Purebred series, offers improved harmonics, fit, and finish.