Description
TM 9-2300-224-10/2/6 M125A1 / T257E2 81mm Self-Propelled Mortar Operator's Manual – March 1966
Item Overview
TM 9-2300-224-10/2/6 is a U.S. Army operator's manual for the M125A1 81mm self-propelled mortar, also identified as T257E2. This March 1966 publication is Part Six of the M113A1 vehicle-family operator's manual series. The copy offered has the current pages from Change 1, dated June 11, 1968, integrated. It is a period reference for collectors and researchers studying tracked mortar carriers during the Vietnam War era.
Identification and Features
The publication number, part designation, and Federal Stock Number identify this manual's place in the Army's technical reference system. These details help match the volume to the correct vehicle and edition.
- Manual number: TM 9-2300-224-10/2/6.
- Publication type: Operator's Manual, Part Six.
- Base publication date: March 1966.
- Included update: Change 1, June 11, 1968, with current pages integrated.
- Equipment: 81mm M125A1 / T257E2 self-propelled mortar.
- Federal Stock Number: FSN 2350-071-0732.
- Issuing authority: Headquarters, Department of the Army.
Function and Contents
As an operator's manual, this volume supports crew use and operator-level care of the specialized mortar carrier. Its subject is the M125A1's role and equipment within the wider M113A1 vehicle family. The Part Six format places this vehicle-specific reference alongside the series' general carrier instructions. For historical research, it helps connect the Army's equipment names and crew responsibilities with the vehicle they supported.
Publication History
The March 1966 issue belongs to a period when the Army used separate manual parts to cover specialized members of the M113A1 family. Change 1 followed in June 1968. Integrating its current pages kept the reference updated through the Army's page-replacement system. This edition records both the base publication and that later update, making the change status an important part of its identity.
Documented Applications
The documented application is the M125A1 tracked carrier equipped for an 81mm mortar. T257E2 is the earlier designation retained in the publication's equipment title. This vehicle combined an armored carrier with a dedicated mortar compartment, allowing the crew, weapon, and ammunition to travel together. Matching the model designation and stock number is useful when selecting period references for an M125A1 restoration or museum display.
Equipment History
The M125A1 grew from the M113 armored personnel carrier family developed by FMC. The Army began accepting the original M113 in 1960, and the diesel-powered M113A1 entered service in 1964. The mortar carrier shared the family's aluminum armor, tracked suspension, and diesel power train. Its specialized rear compartment and large roof hatch made room for the mortar installation. Using common carrier components helped units support several vehicle roles within the same armored force.
Weapon-System Background
The M125A1 carried an 81mm M29-series mortar for indirect fire support. Mortars send rounds along a high, curved path to support troops beyond the crew's direct view. The carrier's internal mounting system allowed a full circle of traverse through the open roof hatch. Ground-mount equipment was also carried for dismounted use. A .50-caliber machine gun supplied local defense, while the vehicle carried the mortar crew and its ammunition.
History of Use
The M125A1 saw documented service in Vietnam with Australian armored units. Australian War Memorial photographs show A Squadron, 3 Cavalry Regiment, firing an M125A1's mortar during Operation Paddington in July 1967. Another record shows a carrier crossing a portable bridge during Operation Matilda in February 1970. These examples illustrate the vehicle's work as mobile mortar support within armored operations. Operator publications supported the training and routine care needed to keep these specialized carriers in service.
Ideal For
This manual fits collections centered on Army technical publications, Vietnam-era armor, and the M113 vehicle family. Its specific model coverage and integrated change pages make it useful for comparing period references and documenting how the Army organized operator information.
- Collectors of U.S. Army technical manuals and military publications.
- M125A1 restorers researching period vehicle identification and operator references.
- Historians studying tracked mortar carriers and Vietnam-era armored units.
- Museums building displays about mechanized infantry and mobile fire support.
Approx length 8", Approx width 10", Approx height .5", Approx weight 1lbs.
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