Description
Technical Manual (TM 9-1005-246-24) for 20mm M139 Automatic Gun April 1969 FSN 1005-999-0896
Add a strong piece of Vietnam War-era / Cold War armored vehicle armament documentation to your collection with this Technical Manual TM 9-1005-246-24 for the 20mm Automatic Gun M139, dated April 1969 and listed with FSN 1005-999-0896.
This manual is documented in related Army technical publications as an Organizational, Direct Support, and General Support Maintenance Manual Including Repair Parts and Special Tools List for the Gun, 20-MM, Automatic, M139.
Historical Significance
The 20mm M139 Automatic Gun is closely tied to the U.S. Army’s Cold War reconnaissance vehicle development. The M139 was the U.S. service version of the Hispano-Suiza HS.820 / Oerlikon KAD 20mm autocannon family, a high-performance automatic cannon design adapted for multiple ground and vehicle applications.
The M139 is especially associated with the M114A1E1 and M114A2 Armored Command and Reconnaissance Carrier. These vehicles used the M139 in the XM27 powered cupola, giving a light tracked reconnaissance platform significantly more firepower than earlier .50 caliber cupola arrangements.
That makes this manual a valuable reference for collectors focused on M114 armored reconnaissance vehicles, XM27 cupola systems, 20mm autocannon equipment, and Vietnam War-era armored vehicle armament.
The 20mm M139 Automatic Gun
The M139 represented the Army’s move toward heavier automatic cannon armament on compact armored vehicles. Instead of relying only on machine gun fire, the M139 gave the M114A2 a 20mm weapon suited for reconnaissance support, suppressive fire, and engagement of light targets.
The gun was part of a broader 20mm ammunition and weapon-system family. Army ammunition references list multiple 20mm cartridges for use with the M139, including M206A1 Target Practice-Tracer, M599 High Explosive Incendiary-Tracer, and M601 Armor Piercing Incendiary-Tracer.
For collectors, the M139 has strong historical value because it sits at the intersection of reconnaissance vehicles, powered cupola design, 20mm automatic cannon development, and the Army’s Cold War search for better vehicle-mounted firepower.
What This Manual Covers
As TM 9-1005-246-24, this publication served as the maintenance and parts-reference manual for the 20mm M139 Automatic Gun at organizational, direct support, and general support levels.
This manual is especially relevant for:
- 20mm M139 Automatic Gun documentation
- M114A1E1 and M114A2 armored vehicle research
- XM27 powered cupola reference collections
- 20mm autocannon maintenance and parts-list research
- Vietnam War-era armored reconnaissance vehicle displays
- U.S. Army ordnance technical manual libraries
- museum and archival reference collections
- collectors completing an M114 / XM27 / M139 technical manual set
Military manuals were official working documents intended to support identification, use, servicing, and field support, which makes them useful to collectors, historians, researchers, and restorers looking for authentic reference material.
Key Features
- Technical Manual TM 9-1005-246-24
- Covers the 20mm Automatic Gun M139
- Dated April 1969
- Listed with FSN 1005-999-0896
- U.S. Army organizational, direct support, and general support maintenance manual
- Includes repair parts and special tools list subject matter
- Connected to the M114A1E1 / M114A2 armored reconnaissance vehicle
- Associated with the XM27 powered 20mm gun cupola
- Strong Vietnam War / Cold War armored vehicle armament collector subject
- Excellent reference for M139, XM27, M114, and 20mm autocannon collectors
About This Manual
This listing is for Technical Manual TM 9-1005-246-24, covering the 20mm M139 Automatic Gun, dated April 1969, with FSN 1005-999-0896.
This listing is for the manual only unless otherwise stated. No automatic gun, cannon, cupola, armored vehicle, ammunition, tools, repair parts, storage case, or additional accessories are included unless specifically shown or noted.
Ideal For
This manual is a strong fit for:
- 20mm M139 Automatic Gun collectors
- M114A1E1 and M114A2 vehicle reference collections
- XM27 powered cupola displays
- Vietnam War armored vehicle collections
- Cold War U.S. Army technical manual collections
- 20mm autocannon reference libraries
- U.S. Army ordnance manual collectors
Approx length 11", Approx width 8", Approx height .5", Approx weight 1lbs.
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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