4.5-inch gun M1

It shared the same carriage with the 155mm howitzer M1 and fired the same ammunition as the British BL 4.5-inch medium field gun.

Beginning in 1944, the weapon was used by the U.S. Army as corps-level artillery; with the end of hostilities, it was declared obsolete.

In 1920 the US Army Ordnance Department started to work on a new medium field gun.

[citation needed] It utilized the same carriage as the concurrently developed 155 mm howitzer.

The breach was of interrupted screw type; the recoil system hydro-pneumatic, variable length.

The shell was produced from low grade ("19 ton") steel, which necessitated thick walls.

Additionally, it was felt that having a small number of guns of an atypical caliber unnecessarily complicated logistics.

155 mm howitzer M1 (left) and 4.5-inch gun M1 (right) at the U.S. Army Field Artillery Museum, Ft. Sill , OK . Note the similarity between the two pieces.