High-res version here.

Paratroopers with A Battery, 4th Battalion, 319th Airborne Field Artillery Regiment, 173rd Airborne Brigade Combat Team, fire an M777A2 cannon during a firing demonstration for visiting Command Sgt. Maj. William Johnson, the command sergeant major for ISAF Joint Command, July 12. The Sky soldiers of the 173rd are on their 4th deployment to Afghanistan in support of Operation Enduring Freedom.