Description
U.S. Army Technical Manual Change 3 TM 9-1290-262-35P for M2 Aiming Circle, December 1964
Item Overview
This U.S. Army publication is Change 3 for TM 9-1290-262-35P, the repair-parts and special-tools manual for the M2 Aiming Circle, FSN 1290-614-0008. Issued in December 1964, it updated the original technical manual dated August 1, 1961. This listing is for the Change 3 update only. It does not include the complete base manual, an aiming circle, tripod, protective cover, instrument light, plumb bob, weapon, or other equipment.
Publication Details
This official change packet was prepared to keep military maintenance and supply personnel current with revisions made after the original manual was published.
- Manual number: TM 9-1290-262-35P
- Update: Change 3
- Change date: December 1964
- Original manual date: August 1, 1961
- Equipment: M2 Aiming Circle
- Federal Stock Number: 1290-614-0008
- Later NSN format: 1290-00-614-0008
- Manual type: Field-and-depot maintenance repair parts and special tools list update
- Issuing authority: Headquarters, Department of the Army
- Country of origin: United States
- Item included: Change 3 update only
About Change 3
Change 3 was issued to revise the working copy of the original parts manual. Army change packets commonly instructed users to remove outdated pages, insert revised pages, and keep the change notice at the front of the publication. This update was intended to be filed with the August 1961 base manual and does not provide the complete contents of that manual by itself.
Manual Coverage
The “35P” suffix identifies the base publication as a higher-level repair-parts and special-tools list. Manuals of this type helped personnel identify authorized assemblies, optical parts, mechanical components, hardware, accessories, and maintenance tools. Change 3 kept that information current as supply data and equipment support requirements changed.
About the M2 Aiming Circle
The M2 Aiming Circle is a portable optical and mechanical instrument used to measure precise azimuth and elevation angles from a selected reference line. Its main parts include a four-power elbow telescope, magnetic compass, graduated scales, micrometer controls, leveling screws, and spirit levels. The instrument was mounted on a tripod and carefully leveled before use.
Equipment Features
The M2 provided unlimited azimuth rotation through a complete 6,400-mil circle. Its fixed-focus telescope offered four-power magnification and a 10-degree field of view. The instrument could measure up to 800 mils of elevation and 400 mils of depression. Circular and tubular levels supported accurate setup, while micrometer controls allowed fine directional adjustments.
- Azimuth rotation: Unlimited through 6,400 mils
- Maximum elevation: 800 mils
- Maximum depression: 400 mils
- Telescope magnification: 4 power
- Field of view: Approximately 10 degrees
- Common supporting equipment: M24 tripod and M51 instrument light
Role in the Weapons System
The M2 was common fire-control equipment rather than a component of only one weapon. Artillery and mortar units used it to place multiple guns, howitzers, or mortars on the same firing azimuth. During reciprocal laying, the aiming-circle operator and weapon crews exchanged angle readings until the sights and weapon tubes were correctly aligned. This allowed several weapons to deliver coordinated indirect fire when their crews could not see the target.
Historical Background
The M2 was documented in Army service by the mid-1950s and became an important surveying and fire-control instrument during the Cold War. The original 1961 parts publication identified the instrument through its M2 and earlier T3-associated nomenclature. By the time Change 3 appeared in December 1964, the standardized M2 designation was established and the Army was continuing to update its maintenance and supply information.
History of Use
Artillery and mortar personnel used the M2 while preparing firing positions, establishing grid or magnetic direction, aligning weapons, measuring horizontal and vertical angles, and conducting field surveys. The December 1964 date places this update near the beginning of the major U.S. military buildup in Vietnam, when portable fire-control instruments remained important to field artillery and mortar units. The M2 later served alongside the improved M2A2 and remained supported in Army publications for many years.
Collector and Research Value
This Change 3 packet documents how the Army revised an active technical publication after its original release. It is useful for completing or studying TM 9-1290-262-35P and for researching M2 Aiming Circle parts, military supply practices, and Cold War artillery equipment. Its separate change status makes it a specialized addition to a technical-manual or military-paper collection.
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 Change 3 update is well suited for collectors, researchers, restorers, and museums interested in military surveying and indirect-fire equipment.
- U.S. Army technical-manual collections
- Completing TM 9-1290-262-35P
- M2 Aiming Circle research
- Artillery and mortar fire-control displays
- Cold War military-document collections
- Museum and archival research
Approx length 8", Approx width 10", Approx height .1", Approx weight .15lbs.
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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