Trulock Black 12 Gauge Full Choke Tube For Beretta These chokes are extended, knurled, and have a black oxide finish. They will normally pattern better than flush mount chokes due to less shot deformation. They are manufactured from high strength 17-4 stainless steel. All precision hunter chokes are marked on the head with the degree of choke and on the body with the bore diameter. This style is an excellent choice for the shooter who wants one choke for both field and clay bird shooting.