Tube for the MP-28 from which the buyer can make a semiautomatic receiver. This tube has a reduced diameter of 1 5/16" and cannot be modified to accept a full auto bolt. The OD has been turned as well as the correct cap threads and barrel threads. The venting holes have been drilled. The CAD drawn template has the other features drawn on it that require machining. The template is a guide that has critical dimensions shown. This can be finished with a dremmel tool, however a milling machine is recommended. Made from American 4130 DOM steel.