A new breech is included in the plans for a future incremental upgrade to the Army's M109A7 self-propelled howitzer, as well as a new gun -- potentially meaning a complete replacement of the vehicle's upper half, program officials told Inside the Army . Toxic fumes released into the howitzer's cab during the first initial operational test and evaluation stemmed from problems with the breech, soldier training, and technical manuals, the Pentagon's director of operational test and evaluation confirmed in an...