Description
20 mm M39 Revolver Cannon Gun Charger Detent Assembly for B-57B/C Canberra, NSN 1005-00-512-0608
The 20 mm M39 revolver cannon gun charger detent assembly is a documented component of the manually operated gun-charger installation used with the cannon armament of Martin B-57B and B-57C Canberra aircraft. Its period package identifies the assembly by FSN 1005-512-0608, later formatted as NSN 1005-00-512-0608.
The label distinguishes the charger reference, P/N 11346, from the packaged detent’s Nobles P/N 11347. This is the detent assembly only, not a complete gun charger, M39 cannon, or aircraft armament installation.
Historical Significance
The B-57 Canberra served the United States Air Force as a Cold War tactical bomber and attack aircraft. Later B-57B production incorporated 20 mm cannon armament, and the B-57C retained close commonality with the B model. This small gun-charger component represents the specialized support hardware required by those aircraft armament installations.
The package was packed in May 1966, placing it within the active service era of the B-57 family and its 20 mm armament system.
B-57B/C and M39 Cannon Relationship
The package marking “APPL. B57 B.C. ACFT” records application to B-57B and B-57C aircraft, while “20 MM MANUALLY OPERATED” identifies the associated gun-charger type. In that installation, the charger served the M39-series 20 mm revolver cannon by providing a manual means of cycling the gun mechanism during ground servicing and preparation.
The offered detent assembly belongs within that charger mechanism. It should be cataloged as a gun-charger component rather than as a complete cannon part set or a general B-57 airframe fitting.
What This Item Is and Does
A detent assembly provides a controlled retaining or indexing action within a mechanical assembly. Here, it is a subassembly of the manually operated 20 mm gun charger associated with the B-57B/C M39 cannon installation.
Its role is limited to the charger mechanism. The assembly does not contain the cannon, ammunition-feed system, firing controls, or the complete manual charger.
Key Features
- Official package nomenclature: Detent Assy., Gun Charger
- Period Federal Stock Number: 1005-512-0608
- Later NSN format: 1005-00-512-0608
- Charger reference on label: P/N 11346, 20 mm manually operated
- Packaged component reference: Nobles P/N 11347
- Documented aircraft application: B-57B and B-57C Canberra
- Associated armament: 20 mm M39-series revolver cannon installation
- Package quantity: 1 each
- Purchase order: 09-603-65-9785
- Package-listed company: Nobles Engineering & Manufacturing Co., St. Paul, Minnesota
- Packing code and date: 111-B, May 1966
Why This Item Matters
Small, identified subassemblies are essential to understanding how an aircraft weapon installation was supported beyond the cannon itself. This detent assembly preserves a traceable link between the M39 gun, its manual charging mechanism, and the B-57B/C Canberra application.
The surviving package data gives the component strong research value by retaining its stock number, two part-number references, aircraft application, contractor information, purchase order, quantity, and packing date.
About This Item
The offered item is one gun-charger detent assembly identified by the photographed military package. The label states FSN 1005-512-0608, P/N 11346, Nobles P/N 11347, application to B-57B/C aircraft, and a quantity of one each.
This is a component for the manually operated charger associated with the B-57B/C 20 mm M39 cannon installation. It is not the complete gun charger, the M39 cannon, an ammunition-feed component, or aircraft mounting hardware.
All items are opened from the original packaging to verify its condition before shipment. If your prefer to receive an item in its original, unopened packaging, please indicate your request in the order comments at checkout. Please Note: If you request an item in its original, unopened packaging, we are unable to verify the item's condition prior to shipment.
Ideal For
This identified aircraft-armament component is a strong fit for:
- B-57 Canberra restorers and museum collections
- M39 revolver-cannon and aircraft-armament researchers
- Cold War United States Air Force equipment displays
- Military aviation parts and packaging collectors
- Technical reference and pattern collections
Approx length 1", Approx width 0.25", Approx height 0.25", Approx weight 0.1 lbs.
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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