51 of these weapons were mounted on 2.5-ton White trucks for anti-aircraft (AA) use, designated the AA truck mount M1917. Some of these weapons reached France before the Armistice, the only US-made AA weapons to do so. These weapons saw some action prior to the war's end and shot down their first aircraft on May 18th, 1918 when soldiers of the U.S. 2nd Anti-Aircraft battery downed a German observation plane over no-man's land. Prior to the commencement of this program, 50 AA truck mounts were shipped to France without guns as a stopgap, where French 75s were mounted on them. The maximum AA altitude was at 82° elevation, limited by a 20-second fuse. The low muzzle velocity and limited elevation and traverse of the AA mounting (31° to 82° elevation, 240° traverse) impaired the weapon's effectiveness. By 1940 the AA version of the weapon was no longer in active service, but a few were retained for training.