Section 160.028-4 - Approval and production tests(a)Approval test. An independent laboratory accepted by the Commandant under § 159.010 of this chapter must test three pistols in accordance with the operational test in paragraph (c) of this section.(b)Production inspections and tests. Production inspections and tests of each pistol must be conducted under the procedures in § 159.007 of this chapter. Each pistol which passes the production inspections and tests must be stamped with the letters "P.T." Each pistol which fails the test must not be represented as meeting this subpart or as being approved by the Coast Guard. (1)Inspections and tests by the manufacturer. The manufacturer's quality control procedures must include the inspection of the pistols during production, and inspection of the finished pistols, to determine that the pistols are being produced in accordance with the approved plans. Each pistol must be tested in accordance with the operational test in paragraph (c) of this section, except that checking of the chamber and bore dimensions is not required.(2)Inspections and tests by an independent laboratory. An independent laboratory accepted by the Commandant under § 159.010 of this Chapter must inspect and test three pistols at least one each year. The inspection must determine that the pistols are being produced in accordance with the approved plans. The test must be in accordance with paragraph (c) of this section.(c)Operational test. The operational test must be conducted as follows: (1) Check the chamber and bore dimensions of the pistol.(2) Fire a dummy cartridge simulating a normal signal in size and weight, but with a charge double the normal charge.(4) Recheck the chamber and bore dimensions.(5) The pistol must fire the signal properly, must not have any visible deformation or damage as a result of the test, and must not have any change in the chamber and bore dimensions.