The Effects of obturators on gun tube wear

Description

Technical report BRL-TR-2996, Ballistic research laboratory Aberdeen Proving Ground, Maryland, 1989, - 21 p.Modern US projectiles incorporate plastic obturator bands to reduce the ill effects of high temperature gas escaping from behind the projectile. Not all NATO countries use obturators on their projectiles. Currently several of these countries are considering introducing obturators to their projectile inventory. This study was conducted primarily to assess the effects of such a change on previously quantified ammunition interchangeability and gun wear. Of particular interest are potential effects on nuclear projectiles. Instrumentation employed included embedded gun tube wall thermocouples. These thermocouples were located at selected circumferential and axial locations. The axial locations were selected to measure charge temperature input to the gun tube wall at locations reflecting various countries current choices of gun tube condemnation measurement points. The circumferential separation of thermocouples allowed continued studies of asymmetric wear effects of stick propellants. Data comparing US and other NATO propelling charges and projectiles, with and without obturators, are presented and analyzed. Additional data on asymmetric heating effects of stick propelling charges are examined.Introduction. Background. Description of material, instrumentation, and techniques. Experimental results and observations. Acknowledgments.