After countless calls about our Canooter being too tight, we fed it some Wheaties and opened it up to .30 Cal. The Dirty Thirty is meant to swallow your larger caliber rounds. Hearing sale on a 300WM so your 300 Black Out will sound like a gaseous emission. Just like our original Canooter Valve, the Dirty Thirty was designed to be compact, robust and still keep the cost of owning a suppressor under $500 including the cost of a NFA stamp.