Description
Incomplete 25x137mm AP Engineering-Test Projectile, Possible GD-OTS NEF / Enhanced PGU-20
Item Overview
This incomplete 25x137mm armor-piercing engineering-test projectile most likely came from General Dynamics Ordnance and Tactical Systems’ developmental NEF program. NEF stands for “Non-Energetic Fragmenting,” and GD-OTS described the design as an Enhanced PGU-20 for the F-35 Lightning II’s GAU-22/A cannon.
Identification and Markings
Item type: Incomplete armor-piercing engineering-test projectile
Caliber: 25x137mm
Visible nomenclature: 25MM AP
Drawing or part number: 1397AS1001
Lot marking: OLM08L001S230
Manufacturer code: OLM, associated with GD-OTS Marion, Illinois
Date code: November 2008
Interfix: 001
Lot identifier: S, special engineering or proving-ground lot
Lot sequence: 230
Probable program: 25mm NEF / Enhanced PGU-20
Associated cannon: GAU-22/A
Associated aircraft: F-35 Lightning II
Probable NEF Construction
The official GD-OTS NEF presentation shows an aluminum projectile body, sintered-iron rotating band, advanced tungsten core, and two-piece nose cap. These features closely match the photographed construction of this specimen. The projectile appears to be missing its forward aerodynamic nose cap or windscreen, and the photographs cannot establish whether the internal penetrator remains.
Lot-Number Information
The OLM08L001S230 marking follows the military ammunition lot-number format. OLM identifies the manufacturing location, 08 indicates 2008, L represents November, and 001 is the interfix number. The letter S identifies a proving-ground, engineering, special-requirement, or special-test lot; it does not mean safe, empty, or inert.
NEF Program History
GD-OTS and the Army Research, Development and Engineering Center developed the 25mm NEF cartridge for the Joint Strike Fighter program. The design was intended to combine armor penetration against ground targets with controlled mechanical fragmentation against thin-skinned aerial targets. The advanced tungsten core provided penetration, while the aluminum body and two-piece nose construction were designed to break into a useful fragment pattern after impact.
NEF and PGU-20 Identification
The documented program abbreviation is NEF, meaning Non-Energetic Fragmenting; “NES” could not be confirmed as an official designation. Non-energetic describes a fragmentation method that does not depend on an explosive projectile filler, but it does not establish that an individual component is safe or inert. Drawing number 1397AS1001 follows a NAVAIR-style engineering-number format, although its exact drawing title is not publicly indexed.
Safety Notice
Legacy PGU-20 armor-piercing projectiles may contain depleted uranium, while the documented NEF design used an advanced tungsten core. Because this incomplete specimen’s internal contents have not been confirmed, it should not be scraped, cut, drilled, machined, heated, polished, or disassembled. Any unknown penetrator should be identified by qualified EOD or radiological personnel before restoration or invasive inspection.
Condition
This is an incomplete engineering-test projectile that appears to be missing its forward cap or windscreen. The presence and material of an internal penetrator have not been confirmed. This listing is for the projectile assembly only; a cartridge case, primer, propellant, cannon, ammunition link, and other components are not included unless specifically pictured or stated.
Ideal For
This projectile is well suited for experimental-ammunition collections, GD-OTS development displays, F-35 and GAU-22/A exhibits, NAVAIR research, modern aircraft-armament collections, museums, and technical study. Its special-test lot marking and incomplete construction provide a rare look at the engineering process behind modern 25mm ammunition.
Approx length 7.5", Approx width 1.5", Approx height 1.5", Approx weight 0.6lbs.
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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