Sgt. Mackenzie testing guns at the Aberdeen Proving Grounds, MD on Oct. 28, 1918. The photo shows an 8" piece elevated and transversed across the track. Please note that this image is not for publication and is for official use only. Issued notes: 24074.

---

Size: 8321px × 5651px
Photo credit: © piemags/NSC / Alamy / Afripics
License: Licensed
Model Released: No

Keywords: 1, aberdeen, activities, american, ammunition, archives, armed, army, artillery, base, defense, development, documents, drills, effort, equipment, exercises, firearms, firepower, forces, grounds, gun, guns, historian, historical, history, logistics, mackenzie, manufacturing, maryland, military, operations, personnel, photograph, practice, precision, preparations, proving, range, research, secret, secrets, serge, sergeant, soldier, states, target, technology, testing, time, top, training, united, war, weapon, weapons, world