Description
This XM27 20mm Gun Mount Manifold Assembly, identified by FSN 1005-867-5358 and Part Number 21770, is a specialized military-surplus component associated with the powered 20mm gun mount / cupola equipment family. For collectors of U.S. military ordnance parts, armored vehicle support components, 20mm gun mount hardware, and stock-numbered surplus items, this is a focused reference piece with strong catalog and display value.
A Department of the Army repair-parts manual, TM 9-1005-307-24P, covers the Cupola, Powered, 20-MM Gun Mount, XM27, along with related M26 powered and manual cupola equipment. In that manual, FSN 1005-867-5358 is listed as a Manifold Assembly, with reference number 21770 and manufacturer code 10237, shown as Figure 70, Item 23.
The XM27 20mm Gun Mount System
The XM27 powered 20mm gun mount belongs to the broader family of armored vehicle cupola, gun mount, and ordnance support equipment. It was documented in military repair-parts literature alongside the powered and manual M26 .50 caliber cupola systems, making this part relevant to collectors who focus on armored vehicle weapon stations, 20mm gun mount components, and Cold War-era vehicle armament support hardware.
The manual scope identifies TM 9-1005-307-24P as a repair-parts and special-tools list for organizational, direct support, general support, and depot maintenance of the XM27 Power Cupola, M26 Power Cupola, and M26 Manual Cupola. The same manual also provides usable-on codes for the cupola applications, including A for XM27 Power Cupola, B for M26 Power Cupola, and D for XM27 and M26 Power Cupola.
For collectors, this gives the manifold assembly added appeal. It represents a specific cataloged component from a specialized gun mount system rather than a generic surplus fitting or hardware item. It fits especially well in collections focused on XM27 cupola parts, 20mm gun mount components, M26 cupola equipment, armored reconnaissance vehicle hardware, and U.S. Army ordnance support systems.
Known Catalog Details
Known identifying information for this item includes:
- Item: XM27 20mm Gun Mount Manifold Assembly
- Catalog Nomenclature: Manifold Assembly
- Federal Stock Number: FSN 1005-867-5358
- Modern NSN Reference: 1005-00-867-5358
- Part Number / Reference Number: 21770
- Manufacturer Code Listed in TM: 10237
- Public CAGE Reference: 10237 – Cadillac Gage Textron Inc.
- Federal Supply Class: 1005 – Guns, through 30mm
- SMR Code Listed: PAFZZ
- Unit of Measure: EA
- Quantity Included in Unit: 1
- Manual Reference: TM 9-1005-307-24P
- Illustration Reference: Figure 70, Item 23
- Included Item: Manifold assembly only
Public supply references list 1005-00-867-5358 under the modern NSN format, while the Army manual lists the older FSN 1005-867-5358 format. Public FSC references identify FSC 1005 as Guns, through 30mm.
One important application note: the available Army repair-parts manual line for FSN 1005-867-5358 / P/N 21767 shows usable-on code B, which the same manual defines as M26 Power Cupola. Because TM 9-1005-307-24P is a combined repair-parts manual covering both XM27 and M26 cupola systems, buyers should verify exact fitment against their own mount, parts list, or technical documentation before purchase.
What This Manifold Assembly Supports
As a 20mm gun mount / powered cupola manifold assembly, this item is best understood as a support component for a larger military mount system. It is not a complete gun mount, not a cupola assembly, not a cannon, not ammunition, and not an explosive item.
In practical collecting and display terms, a component like this is especially relevant for:
- XM27 20mm gun mount component collections
- M26 powered cupola reference collections
- armored vehicle ordnance hardware displays
- Cold War-era vehicle armament support collections
- U.S. military surplus parts inventories
- museum exhibits on armored vehicle weapon stations
- collectors of FSN / NSN and part-numbered ordnance components
- buyers seeking P/N 21770 or FSN 1005-867-5358
Because this is a specific part-numbered component, buyers working on a restoration, inventory, or display project should confirm compatibility with their own technical manuals and equipment records.
Historical and Technical Interest
Small components like this Manifold Assembly help preserve the support story behind larger armored vehicle gun mount systems. While complete cupolas, vehicles, and weapons receive most of the attention, military systems depended on individual manifolds, valves, fittings, pins, springs, covers, brackets, and control components to remain documented and maintainable through official supply channels.
For collectors and historians, this manifold assembly is especially relevant to subjects such as:
- XM27 powered 20mm gun mount components
- M26 powered cupola parts
- Cold War armored vehicle armament hardware
- 20mm gun mount support equipment
- U.S. Army repair-parts documentation
- FSN and NSN military surplus components
- Cadillac Gage-related cupola equipment
Because this item is identified by both FSN 1005-867-5358 and P/N 21770, it has stronger reference value than an unmarked or generic surplus manifold. It helps document the detailed supply and maintenance system behind U.S. armored vehicle gun mount equipment.
About This Manifold Assembly
This listing is for one XM27 20mm Gun Mount Manifold Assembly, identified as FSN 1005-867-5358 and P/N 21770.
It is especially well suited for:
- XM27 gun mount parts collectors
- M26 powered cupola component collections
- armored vehicle ordnance displays
- Cold War military surplus collections
- museum and archival reference use
- restoration-support reference collections
- collectors of FSN / NSN-identified military hardware
- buyers seeking P/N 21770 or NSN 1005-00-867-5358
This listing is for the manifold assembly only unless otherwise stated. No complete cupola, gun mount, cannon, vehicle, ammunition, hydraulic system, tools, manuals, fittings, or additional accessories are included unless specifically shown or noted.
Why This Manifold Assembly Matters
Many military collectibles focus on complete weapons, vehicles, uniforms, helmets, or technical manuals. This item represents a different but equally important category: the individual components that kept larger ordnance systems documented, maintained, and supplied.
For collectors, it is a compact and highly specific military component with clear FSN, part-number, and manual-reference value. For researchers, it provides a useful example of how powered cupola components were cataloged in U.S. Army repair-parts documentation. For museums and displays, it helps show the behind-the-scenes hardware that supported armored vehicle gun mount systems during the Cold War period.
Because this item is tied to the XM27 / M26 powered cupola equipment family and carries the traceable identification FSN 1005-867-5358 and P/N 21770, it is a strong fit for anyone building a focused collection of U.S. armored vehicle ordnance components, 20mm gun mount parts, or government-surplus cataloged hardware.
Ideal For
This manifold assembly is a strong fit for:
- XM27 20mm gun mount component collections
- M26 powered cupola reference displays
- armored vehicle ordnance hardware collections
- Cold War U.S. Army surplus displays
- military vehicle restoration-reference collections
- museum and archival display setups
- buyers seeking P/N 21770 or FSN 1005-867-5358
Approx length 5.5", Approx width 4", Approx height 4", Approx weight 4lbs.
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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