Description
U.S. Army M17A1/M17C Tank Rangefinder End-Box Housing Assembly
Item Overview
This U.S. Army optical end-box housing assembly was made for the M17 series of tank fire-control rangefinders. It formed one of the two outboard optical housings on the rangefinder and helped gather the external view used to measure target distance. This is an inert military-surplus optical component, not a complete rangefinder or an explosive item.
Identification and Features
The official federal name is Housing, Fire Control Instrument. Seiler Precision also identifies P/N 10516328 as a rangefinder end-box housing. The visible center cover and surrounding plate markings match parts listed in the assembly’s bill of materials.
- Official name: Housing, Fire Control Instrument
- Common name: Rangefinder end box or end housing
- Part number: 10516328
- NSN: 1240-00-865-7695
- Center cover: P/N 8585517
- Surrounding plate or ring: P/N 8585519
- Internal optical window: P/N 8200495
- Internal cell assembly: P/N 10516319
- Internal penta prism: P/N 8635363
- Documented rangefinders: M17C, M17A1, and M17B1C
- Documented vehicles: M60, M60A1, and M48A5 tanks
- Status: Inert fire-control instrument component
How the End Box Worked
The end housing held an optical window and Penta prism at the outer end of the rangefinder. Light from the target entered through the window, and the prism turned the light path 90 degrees into the main instrument body. The operator adjusted the coincidence rangefinder until its two target images formed one clear image, allowing the system to indicate range. The housing was sealed and dry-nitrogen purged to reduce moisture and internal fogging.
M17 Rangefinder Configuration
P/N 10516328 appears in Army parts information for the M17C, M17A1, and M17B1C rangefinders. This assembly’s cylindrical shape and single outlet or relief fitting match the M17A1 and M17C end assembly shown in Army Figure 3-45. The complete M17B1C used a different end arrangement with two outlet screws, so this item is most accurately described as an M17A1/M17C-pattern housing that was also cataloged within the M17B1C system.
Tank and Weapon Applications
This end-box assembly was used with M17-series rangefinders fitted to M60, M60A1, and M48A5 tanks. These vehicles carried the 105 mm M68 family of main guns. Range information from the optical instrument supported the tank’s mechanical fire-control system and helped crews aim more accurately at distant targets. The M60A1 and rebuilt M48A5 remained in military service for many years, while upgraded M60A1 tanks saw operational use through the Persian Gulf War era.
Historical Background
The M17 family represents the mechanical and optical fire-control technology used before laser rangefinders became standard. The M60 entered service in 1959, followed by the improved M60A1 during the early 1960s. The M48A5 modernization program later combined rebuilt M48 hulls with a 105 mm gun and updated fire-control equipment. M17-series instruments served through this transition and supported tank gunnery during the Cold War, training exercises, overseas deployments, and combat operations.
Condition
This is a military-surplus optical housing assembly and may show storage wear, scratches, finish loss, oxidation, dust, old preservative, or handling marks. The carton identifies General Aero Products Corporation as the contract manufacturer. Its 10/80 marking is best treated as an October 1980 packing or carton date rather than a confirmed manufacture date. Optical condition, sealing, nitrogen retention, alignment, and serviceability have not been tested. This listing is for one end-box housing assembly only; the complete M17 rangefinder, tank, mounting hardware, and other fire-control components are not included unless specifically stated. Please check the pictures for the general condition of the item.
Ideal For
This authentic component is well suited for military-vehicle restoration, fire-control research, museum exhibits, technical study, and collections focused on American Cold War armor.
- M60 and M60A1 tank displays
- M48A5 restoration projects
- M17 rangefinder collections
- Cold War fire-control exhibits
- Military optics research
- Armor museums and educational displays
Approx length 10", Approx width 6", Approx height ", Approx weight lbs.
Pictures are stock images of our inventory. Unless otherwise noted, you will not be receiving the exact item shown in the pictures. The pictures are representative of the item’s general condition. The item you receive might be slightly better, or worse, condition than was shown in the pictures.
Please visit our page about order lead times here: Order Lead Times.