Product Overview: Quadrant, Fire Control: Range, M4A1
NSN:  1290-00-759-7761
P/N: 7597761

General Description
Quadrant, Fire Control: Range M4A1 is a manually operated elevation indicating instrument used for laying howitzers and cannons in elevation for indirect fire. The quadrant is mounted so that any movement of the howitzer in elevation is imparted to the quadrant. It consists of the battery bracket assembly, the longitudinal and cross level vial tube assemblies, cross leveling mechanism assembly, the range elevating mechanism, the angle-of-site mechanism, and a built-in illuminating system which provides illumination of the instrument for night operation. When laying the piece, the required angle of elevation is set on the elevation scale and the longitudinal level vial is tilted, and the howitzer is elevated until the level bubble is centered, thus indicating that the piece is laid to the desired elevation.

The range fire control quadrant M4A1 is used with Cannon, 105mm Howitzer: M2A2 and Cannon, 75mm Gun: Automatic, M35 and T83E6.