Description
Add a specialized piece of U.S. military fire-control optics history to your collection with this M109 Telescope Elbow, identified by Serial Number 18239, Part Number 8588780, and NSN 1240-00-823-5612. This is a precision optical sighting component associated with mortar and rocket-launcher fire-control equipment, not a general commercial telescope or spotting scope.
Public NSN records identify 1240-00-823-5612 as Telescope, Elbow, with P/N 8588780, classified under FSC 1240 – Optical Sighting and Ranging Equipment. The same listing defines an elbow telescope as a telescope whose line of vision is bent 90 degrees.
Historical Significance
The M109 Elbow Telescope was part of the U.S. military’s optical sighting and fire-control equipment family. It was used with the M128 and M128A1 Telescope Mounts, and together these components formed the M53 / M53A1 Sight Unit. Military specification material states that the M109 elbow telescope and M128/M128A1 mount were employed with mortars and rocket launchers.
That makes this item especially appealing for collectors of mortar sights, field fire-control instruments, rocket-launcher sighting equipment, and U.S. Army optical instruments. It represents the practical aiming equipment behind indirect-fire systems, where accurate azimuth and elevation reference mattered as much as the weapon itself.
The M109 Elbow Telescope
The M109 was used as the optical portion of the sight unit. A field manual reference describes the Elbow Telescope M109 as a lightweight, 4-power, fixed-focus instrument with a 10-degree field of view. It provided the optical line of sight for aiming the weapon in both azimuth and elevation.
The same reference notes that the M109 incorporated a reticle with graduated mil markings and could be positioned for different viewing arrangements. That made it useful in field conditions where the operator needed a practical optical sighting solution for laying mortars or related indirect-fire weapons.
Known Identification Details
- Item: M109 Telescope Elbow
- Serial Number: 18239
- Part Number: 8588780
- NSN: 1240-00-823-5612
- NIIN: 00-823-5612
- Catalog Nomenclature: Telescope, Elbow
- Federal Supply Class: 1240 – Optical Sighting and Ranging Equipment
- Associated Sight Unit: M53 / M53A1
- Associated Mounts: M128 / M128A1 Telescope Mounts
- Associated Use: Mortar and rocket-launcher fire-control sighting equipment
- Included Item: Telescope elbow only, unless otherwise shown or stated
Army maintenance documentation for the 81mm Mortar M29A1 lists the Elbow Telescope M109, P/N 8588780, within the Sight unit M53/M53A1 group, confirming its place in the military mortar sighting equipment family.
Why This Item Matters
The M109 Telescope Elbow helps tell the story of how U.S. crews aimed and laid indirect-fire weapons before modern digital sighting systems. It was part of the precision optical equipment used to align weapons by azimuth and elevation, supporting accurate fire-control work in the field.
For collectors, this is a focused and desirable optical component. It pairs well with M53/M53A1 sight unit displays, M128 telescope mount references, 81mm mortar collections, rocket-launcher sighting equipment, fire-control instrument displays, and Cold War U.S. Army optics collections.
About This Telescope Elbow
This listing is for one M109 Telescope Elbow, identified by Serial Number 18239, P/N 8588780, and NSN 1240-00-823-5612.
This listing is for the telescope elbow only unless otherwise stated. No complete sight unit, M128/M128A1 mount, mortar, rocket launcher, instrument light, carrying case, tool kit, manuals, or additional accessories are included unless specifically shown or noted.
This item is intended for collection, display, restoration reference, historical research, or military optical instrument study.
Ideal For
This telescope elbow is a strong fit for:
- M109 Telescope Elbow collectors
- M53 and M53A1 sight unit displays
- M128 / M128A1 telescope mount reference collections
- 81mm mortar and indirect-fire equipment displays
- Cold War fire-control instrument collections
- U.S. Army optical instrument collectors
- museum and archival ordnance exhibits
- collectors of NSN and part-numbered military optics
Approx length 10", Approx width 8", Approx height .2", Approx weight .2lbs.
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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