WMD Guns 9mm 16.5in Medium Profile 1-10 RH 4150 CrMoV 1/2-28 Nitride Black 9MMB16.5 1-10MP. Barrel has a Nitromet nitrided bore treatment for longer life than chrome without affecting accuracy. Barrels are made of 4150 CrMoV chambered for 9mm button...