Characterization of Bore Temperatures and Stresses in Small Caliber Gun Barrels

Data gathered from physical testing will be compared to analytical methods used to assess barrel wall temperature profiles and barrel wall stress and strain.

Army Armament Research, Development and Engineering Center, Picatinny Arsenal, New Jersey

Currently in the small arms community, with the push for lighter, stronger barrels with improved life, a more complete understanding of the bore's thermal and structural behavior is required in order to not only improve future barrel design but to more thoroughly and accurately assess barrels in the current inventory.

The environment within a small caliber gun barrel during a firing event is extreme. As a round is fired, hot, pressurized gases are produced, ranging in the thousands of degrees Fahrenheit (°F) and up to and beyond 62,500 lb per square inch (psi), all within 1 ms. Moreover, in an automatic weapon such as a machine gun, the barrel's steady state temperature quickly increases as more rounds are fired in succession with the outer surface of machine gun barrels reaching higher than 1,000°F.