SRM Terror choke tube Browning Invector 10 Ga .720'' The Terror Chokes were originally developed by SRM Performance Products to shoot consistently dense and tight long-range patterns with the new "fast steel" shells and hand-loading. However, they also deliver just plain amazing radial-constriction choke tube performance, at any velocity and with all shot material types.  These tubes are top USA-MADE quality in design, materials, quality control, tolerances and precision workmanship, and are designed with safety in mind so as to prevent the tube from "shooting loose" in the field.