Description
105-mm Howitzer M49 Breechblock Operating Crank, P/N 7305293, NSN 1015-00-730-5293
The 105-mm Howitzer M49 Breechblock Operating Crank, identified by part number 7305293 and NSN 1015-00-730-5293, is a steel component of the M49 howitzer's breech-operating system. The M49 was installed in the 105-mm Howitzer Mount M85, which equipped the M52 and M52A1 self-propelled howitzers.
Its internally splined hub connects with the breech-operating shaft. The crank transfers movement through the breech-operating group to help open and close the M49's vertical-sliding breechblock.
Historical Significance
The M49 howitzer, M85 mount, and M52-series self-propelled chassis formed a U.S. armored artillery system of the early Cold War. The arrangement placed the 105-mm weapon in an enclosed, limited-traverse turret while retaining a mechanically operated vertical-sliding breechblock.
TM 9-500 identifies the M49 and M85 as the major weapon components used in both the M52 and M52A1. The operating crank is part of the breech mechanism that served this vehicle-mounted artillery installation.
M49, M85, and M52-Series Relationship
The M49 designation belongs to the 105-mm howitzer, while M85 identifies its mount. Together they formed the primary armament installation in the M52 and M52A1 self-propelled howitzers.
TM 9-1015-211-34, Figure 6, labels the component directly as Breechblock Operating Crank - 7305293 on the right rear of the M49 breech. This distinguishes it from the adjacent operating-handle assembly, operating-handle bracket, breech ring, and breechblock group.
What This Item Is and Does
The 105-mm Howitzer M49 Breechblock Operating Crank is a hub-and-arm component positioned at the right side of the M49 breech ring. Its internal spline engages the breech-operating shaft, allowing rotational movement to pass through the crank into the breech operating mechanism.
The M49 uses a vertical-sliding breechblock that travels within the machined interior of the breech ring. The operating crank helps translate movement from the operating-handle and shaft arrangement into the mechanism that raises and lowers that breechblock.
Catalog data describes the crank as steel with a 4-inch overall length. It has a 2.623-inch outside diameter at one end, a 3.5-inch outside diameter at the other end, a 1.375-inch crank-handle diameter, and a 2.032-inch-diameter SAE standard ten-spline internal form.
Key Features
- Official name: Crank, Operating
- Manual identification: Breechblock Operating Crank
- Part number 7305293
- National Stock Number 1015-00-730-5293
- Documented for the 105-mm Howitzer M49
- Used with the 105-mm Howitzer Mount M85
- Supported end items: M52 and M52A1 self-propelled howitzers
- Internally splined hub for the breech-operating shaft
- 2.032-inch-diameter SAE standard ten-spline internal form
- 4-inch overall length
- Cataloged steel construction
- Exact component labeled in TM 9-1015-211-34, Figure 6
Why This Item Matters
The 105-mm Howitzer M49 Breechblock Operating Crank is a precisely identified part of the M49 breech-operating system. Its part number, NSN, catalog dimensions, spline form, and illustrated position provide strong documentation for accurate component identification.
It is useful for M49 howitzer and M52-series restoration research, military-vehicle displays, artillery component collections, museum reference work, and the study of early Cold War self-propelled artillery mechanisms.
About This Item
The offered item is one 105-mm Howitzer M49 Breechblock Operating Crank, official nomenclature Crank, Operating, with P/N 7305293 and NSN 1015-00-730-5293. Its documented application is the M49 howitzer in the M85 mount used by the M52 and M52A1 self-propelled howitzers.
The cataloged overall length is 4 inches. The component has a 2.032-inch-diameter SAE standard ten-spline internal form that connects with the breech-operating shaft. Figure 6 of TM 9-1015-211-34 identifies the crank separately from the adjacent operating-handle assembly and breechblock components.
Ideal For
This item is a strong fit for:
- M49 105-mm howitzer collections
- M52 and M52A1 restoration research
- M85 howitzer-mount displays
- U.S. self-propelled artillery collections
- Early Cold War military-vehicle exhibits
- Museum and educational reference collections
- Historic breech-mechanism study
- Film and prop department reference
Approx length 4", Approx width 5", 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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