THE PRODUCTION OF PRESSURE WAVES IN THE 5-IN/38-CALIBER BLOWOUT GUN
Partial rept. no. 2
NAVAL PROVING GROUND DAHLGREN VA
Pagination or Media Count:
The possibility of producing pressure waves in the chamber of the blowout gun and the degree to which breech pressure records from a standard 5- in.38-cal gun could be reproduced were determined. The charge used in the tests was 15.53 lb of NPFB-234 at 90 F. One series of firings was made to establish the conditions under which pressure waves could be produced in the blowout gun. A second series of firings was made to compare breech pressure curves obtained from the blowout gun, with similar cartridge case loading conditions in both guns. In this series, 4 types of experimental primers and 1 standard primer were used. Pressure times curves were obtained on all rounds at the base of the case and at 3 positions along the chamber of the blowout gun. Results indicated that pressure waves can be produced in the blowout gun. The wave configuration obtained in a 5-in38-cal gun can be duplicated closely in the blowout gun over a wide range. The velocity of the burning front in the charge was directly proportional to the weight of the black powder used in the primer tube and varied from 900 to 1300 fps for the primers used.