Description
U.S. Army Technical Manual TM 9-1290-357-15 for M1 Aiming Circle W/E, March 1970
Item Overview
This U.S. Army technical manual covers the operation and maintenance of the M1 Aiming Circle W/E, FSN 1290-671-6145. Issued on March 19, 1970, it was written for operators, unit mechanics, and higher-level maintenance personnel. The publication also includes repair-parts and special-tools information. This listing is for the technical manual only. It does not include an aiming circle, tripod, light, cover, carrying case, weapon, or other equipment.
Publication Details
TM 9-1290-357-15 served as a complete reference for operating, inspecting, maintaining, repairing, and testing the M1 Aiming Circle and its issued equipment.
- Manual number: TM 9-1290-357-15
- Publication date: March 19, 1970
- Subject: M1 Aiming Circle W/E
- Federal Stock Number: 1290-671-6145
- Manual level: Operator, organizational, direct support, general support, and depot maintenance
- Additional contents: Repair-parts and special-tools lists
- Issuing authority: Headquarters, Department of the Army
- Country of origin: United States
- Earlier publication: Superseded M1 coverage in TM 9-1530 dated March 21, 1950
- Item included: Technical manual only
Manual Coverage
The manual explains the M1 Aiming Circle’s controls, setup, leveling, operation, inspection, and preventive maintenance. It covers measuring horizontal and limited vertical angles, orienting from magnetic north or a known reference point, and using the instrument in different field conditions. Higher-level sections provide troubleshooting, disassembly, repair, assembly, adjustment, final testing, storage, and inspection guidance.
About the M1 Aiming Circle
The M1 is a tripod-mounted optical instrument used to orient artillery and infantry weapons. Its telescope, azimuth mechanism, elevation mechanism, levels, and magnetic needle allowed crews to establish direction and measure angles from a known point. The orienting mechanism could turn the complete instrument without changing the azimuth-scale setting, making it useful for transferring an established direction to several weapons.
M1 Aiming Circle Specifications
The manual lists the following operating and physical data for the military instrument and complete equipment set. These specifications describe the equipment covered by the manual, not the dimensions of the manual being sold.
- Telescope magnification: 4×
- Field of view: 10 degrees
- Azimuth range: 0 to 6,400 mils
- Elevation range: Approximately 142 mils above or below horizontal
- M1 instrument weight: Approximately 4 pounds
- M1 instrument dimensions: Approximately 5-1/4 by 5 inches
- Complete set weight: Approximately 21-1/2 pounds
- Instrument-light voltage: 3 volts DC
Equipment Set Described
The abbreviation “W/E” means “with equipment.” The complete military set combined the optical instrument with the support, lighting, protection, and carrying equipment needed for field operation. These components are described in the manual but are not included with this listing.
- M1 Aiming Circle: Optical and mechanical angle-measuring instrument
- M5 Tripod: Adjustable support with telescoping legs
- M2 Instrument Light: Battery-powered light for the reticle and scales
- M409 Aiming Circle Cover: Protective cover for the instrument
- M6A1 Carrying Case: Storage and transportation case for the complete set
Weapon-System History
The M1 Aiming Circle was not limited to one gun or mortar model. It was common fire-control and surveying equipment that helped artillery and infantry units place several indirect-fire weapons on the same direction. This supported coordinated fire from howitzers, guns, and mortars even when crews could not see the target from their firing positions.
Historical Background
The M1 design dates from the World War II period and remained useful for decades. The March 1970 edition replaced M1 instructions found in a 1950 manual, showing the instrument’s long service life. Its mechanical controls, magnetic needle, optical telescope, and illuminated scales represent the field-survey methods used before digital aiming systems, satellite navigation, and electronic position equipment became common.
History of Use
In the field, a crew placed the aiming circle on its tripod, leveled it, and oriented it from magnetic north or a known survey point. The operator then measured angles and transferred a common direction to nearby weapons. Because iron and steel could disturb the magnetic needle, crews had to place the instrument away from large metal objects when using magnetic orientation. The M2 light allowed the scales and telescope reticle to be read during night operations. The 1970 publication places this manual in the Vietnam War and Cold War period, when conventional artillery and mortars remained major parts of Army fire support.
Collector and Research Value
TM 9-1290-357-15 is a useful reference for studying military surveying, indirect-fire procedures, optical instruments, and Army maintenance practices. Its coverage ranges from basic operation through depot repair, making it valuable for collectors, museums, restorers, and researchers working with an M1 Aiming Circle or its accessories.
Condition
This vintage military technical manual may show cover wear, edge wear, folds, yellowing, stains, writing, stamps, punched holes, loose pages, or other signs of age and storage. Printing details and condition may vary between available copies. Please check the pictures for the general condition of the item.
Ideal For
This manual is well suited for collections, restoration projects, research, and displays involving U.S. military fire-control and surveying equipment.
- U.S. Army technical-manual collections
- M1 Aiming Circle restoration research
- Artillery and mortar history displays
- Military surveying-equipment collections
- Vietnam War and Cold War exhibits
- Museum, educational, and archival collections
Approx length 8", Approx width 11", Approx height .35", Approx weight .5lbs.
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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