The Model 45A was a battle rifle / light machine gun developed by the United States Army

United States Army

The United States Army is the main branch of the United States Armed Forces responsible for land-based military operations. It is the largest and oldest established branch of the U.S. military, and is one of seven U.S. uniformed services...

 in the Philippines

Philippines

The Philippines , officially known as the Republic of the Philippines , is a country in Southeast Asia in the western Pacific Ocean. To its north across the Luzon Strait lies Taiwan. West across the South China Sea sits Vietnam...

 in 1945. The weapon existed in prototype or mockup form, but never entered production. The rifle was sparsely documented until Tom Laemlein encountered a number of annotated photographs of the rifle in the archives of the United States Army Signal Corps

United States Army Signal Corps

The United States Army Signal Corps develops, tests, provides, and manages communications and information systems support for the command and control of combined arms forces. It was established in 1860, the brainchild of United States Army Major Albert J. Myer, and has had an important role from...

.

Design

The rifle was constructed in bullpup configuration, utilising the magazine from the M1918 Browning Automatic Rifle. Rather than iron sights

Iron sights

Iron sights are a system of shaped alignment markers used as a sighting device to assist in the aiming of a device such as a firearm, crossbow, or telescope, and exclude the use of optics as in telescopic sights or reflector sights...

, it featured an integral scope. Its purpose is unclear, but it is alternately described as a "experimental .30 caliber LMG

Light machine gun

A light machine gun is a machine gun designed to be employed by an individual soldier, with or without an assistant, as an infantry support weapon. Light machine guns are often used as squad automatic weapons.-Characteristics:...

" or a "field expedient .30 cal."

Users

: Philippine Commonwealth Army

Philippine Army

The Philippine Army is the ground arm of the Armed Forces of the Philippines . Its official name in Tagalog is Hukbong Katihan ng Pilipinas. On July 23, 2010, President Benigno Aquino III appointed Maj. Gen...

 & Philippine Constabulary

Philippine Constabulary

The Philippine Constabulary ' was the oldest of four service commands of the Armed Forces of the Philippines. It was a gendarmerie type para-military police force of the Philippines established in 1901 by the United States-appointed administrative authority replacing the Guardia Civil...

: United States Army Signal Corps

United States Army Signal Corps

The United States Army Signal Corps develops, tests, provides, and manages communications and information systems support for the command and control of combined arms forces. It was established in 1860, the brainchild of United States Army Major Albert J. Myer, and has had an important role from...