Description
U.S. Army Tubular Spring 7650547 for M12A7-Series Panoramic Artillery Telescopes
Item Overview
This U.S. Army Spring, Tubular, part number 7650547, is a steel replacement component for the M12A7 series of panoramic artillery telescopes. Its slotted, ring-shaped design is made for the telescope’s internal optical assembly and should not be confused with an ordinary washer. Army maintenance records identify this spring as a common component used across five documented M12A7 telescope configurations.
Identification and Features
TM 9-1240-236-35P identifies this component in the partial exploded view of the panoramic telescope. Figure 2 places it beside the optical prism and a group of steel alignment shims. The manual lists one tubular spring per telescope assembly and provides the part’s material and exact dimensions.
- Official name: Spring, Tubular
- Part number: 7650547
- Original FSN: 1240-765-0547
- Material: Steel
- Outside diameter: 1.260 inches
- Inside diameter: 1.136 inches
- Thickness: 0.130 inch
- Quantity per telescope: One
- Manual reference: TM 9-1240-236-35P
- Illustration reference: Figure 2, item 23
- Manual reference code: 19200
Historical Background
The M12 panoramic-telescope family was established by World War II, with Army technical manuals covering early M12 variants by 1942. The later M12A7 series continued this proven sighting arrangement in postwar field artillery service. The July 1970 parts manual supported the M12A7C, M12A7H, M12A7K, M12A7Q, and M12A7S through direct-support, general-support, and depot maintenance. Part number 7650547 appears in that manual as an authorized internal repair component shared by the covered telescope models.
Telescope Function
An M12A7 panoramic telescope gave the gunner a rotating azimuth sight for laying an artillery weapon in direction. During indirect-fire missions, the gunner could sight on an aiming post or another established reference point even when the target was not visible from the weapon. Inside the telescope, prisms redirected the optical path while shims established the required fit and alignment. The parts illustration places this tubular spring directly beside the prism and shim group, where its spring tension supported the fitted optical assembly.
Documented Weapon Applications
The Army parts manual assigns individual M12A7 telescope variants to specific howitzers and rocket-launcher equipment. Because the spring’s catalog entry has no model-restriction code, it is listed as a common part for all five telescope variants covered by the manual.
- M12A7H and M12A7S: M101 and M101A1 105mm towed howitzers
- M12A7C and M12A7Q: M114, M114A1, and M123A1 155mm howitzers
- M12A7K: M44 and M44A1 155mm self-propelled howitzers
- M12A7C: M386 762mm rocket launcher
Weapon-System Background
The M101 family began as the M2A1 105mm howitzer and served as a major U.S. light field-artillery weapon during World War II, Korea, and Vietnam. The 155mm Howitzer M1 entered production in 1941 and was later redesignated M114; it provided heavier supporting fire through World War II and remained a standard weapon during the Korean and Vietnam Wars. The M44, produced beginning in 1954, placed a 155mm howitzer on a tracked chassis for mobile Cold War fire support. The 762mm M386 launcher belonged to the Honest John battlefield rocket system, which entered U.S. service during the 1950s. M12A7 telescope variants allowed these different weapons to use a related panoramic-sight design while retaining model-specific installations.
History of Use
During firing operations, artillery crews used the panoramic telescope to place the weapon on the required direction received from fire-direction personnel. The sight allowed a gunner to return to a known aiming reference after each round and helped maintain consistent direction throughout a fire mission. Maintenance personnel serviced internal optical components at higher maintenance levels when a telescope required repair or overhaul. The 7650547 spring supported that maintenance system as a replaceable component within the prism and shim assembly.
Condition
The listing is for one loose steel tubular spring with handwritten identification matching part number 7650547. Its slotted ring construction corresponds with the component illustrated in the Army parts manual. The panoramic telescope, prism, shims, sight mount, and weapon are not included. Refer to the inventory photographs for the finish and visible storage condition of the spring supplied.
Ideal For
This specialized component is suitable for a parts-correct M12A7 telescope project or as a documented example of U.S. Army artillery fire-control hardware. Its confirmed part number, dimensions, and broad application across several telescope variants make it useful for restoration reference and organized spare-parts collections.
- M12A7-series telescope restoration
- M101, M114, and M44 artillery collections
- M386 Honest John equipment displays
- Military optical-instrument collections
- Part-number and manual-reference displays
Approx length 1.260", Approx width 1.260", Approx height 0.130", 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.
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