Description
U.S. Experimental 25x59mm XM307 ACSW Dummy Round with Aluminum Case, Steel Tip, and Feed Link – Marked OL-0507
This 25x59mm dummy cartridge is an original-style developmental ammunition component associated with the XM307 Advanced Crew Served Weapon (ACSW) program. The round has an aluminum cartridge case, steel nose/tip, and original-style steel feed link.
Black markings on the body read “25MM DUMMY” with the additional marking “OL-0507.” Because no authoritative public cross-reference for OL-0507 has been located, that marking is preserved exactly as found rather than being identified as a confirmed part number, lot number, or date code.
This is a dummy round intended for non-firing handling, feed, and mechanical testing, not a live service cartridge.
Historical Significance
The 25x59mm cartridge was developed for the U.S. Objective Crew Served Weapon, later known as the XM307 Advanced Crew Served Weapon. The Army wanted a lightweight weapon that could combine the long-range capabilities of a heavy machine gun with the area effects of an automatic grenade launcher.
The XM307 was developed by General Dynamics and used a belt-fed family of 25mm ammunition. Its advanced fire-control system was designed to support conventional and programmable airburst ammunition, allowing rounds to function near targets protected by walls, trenches, and other cover. The system was intended to supplement or eventually replace some roles performed by the M2 .50-caliber machine gun and Mk 19 40mm grenade launcher.
The Army's 25mm family was designed for effective fire out to approximately 2,000 meters, and the XM307 weapon operated from linked ammunition carried in a weapon-mounted ammunition container. The program reached an advanced development stage during the 2000s but was ultimately shelved as Army priorities changed.
What This Item Is and Does
This is a dummy version of a 25x59mm cartridge.
A dummy cartridge reproduces the basic size, shape, and feeding characteristics of service ammunition without functioning as a live round. In a developmental belt-fed weapon such as the XM307, dummy cartridges could be used for handling demonstrations, ammunition-feed evaluation, link testing, display, and other non-firing purposes.
The steel nose gives the cartridge the proper external projectile profile and may also help reproduce the weight and balance of the intended ammunition. It should not be interpreted as evidence that this particular dummy represents an armor-piercing loading.
25x59mm and the XM307 ACSW
The 25x59mm cartridge is much shorter than conventional 25mm autocannon ammunition such as the 25x137mm round used by the M242 Bushmaster.
Instead of being designed as a traditional high-velocity cannon cartridge, the 25x59mm family was developed around specialized grenade-type projectiles. Developmental loadings included ammunition concepts for:
- Programmable airburst use
- High-explosive effects
- Light-armor engagement
- Training and test purposes
- Dummy and handling applications
The same basic 25x59mm cartridge family was also associated with the experimental Barrett XM109 Anti-Materiel Payload Rifle. The XM109 used cartridges from a detachable magazine rather than the linked feed arrangement of the XM307.
Because this example retains a feed link, its configuration is especially representative of the belt-fed XM307 ammunition system.
The Feed Link
The steel link fitted around the cartridge allowed individual 25x59mm rounds to be assembled into a belt for the XM307's ammunition-feed system.
The XM307 was specifically designed as a belt-fed 25mm weapon, with period General Dynamics documentation describing a weapon-mounted ammunition can and linked ammunition.
The surviving link adds significant display value because it shows how the short 25mm cartridges were supported and guided through the experimental crew-served weapon.
Key Features
- Caliber: 25x59mm
- Type: Dummy cartridge
- Associated weapon: XM307 Advanced Crew Served Weapon
- Associated program: Objective Crew Served Weapon / ACSW
- Country: United States
- Cartridge case: Aluminum
- Nose/tip: Steel
- Feed system: Belt-fed
- Feed link: Included
- Body marking: 25MM DUMMY
- Additional marking: OL-0507
- OL-0507 meaning: Not independently confirmed
- Configuration: Non-firing dummy / handling round
- Period: Experimental late-1990s / 2000s U.S. weapons development
- Quantity: One round with one link
Why This Item Matters
The XM307 represented an ambitious effort to move crew-served weapons beyond conventional machine guns and automatic grenade launchers.
Its 25mm ammunition was a major part of that concept. Instead of relying only on direct impact, the system was being developed around precision fire control and programmable ammunition.
Developmental components such as dummy rounds are especially interesting because they document the engineering and testing process behind weapons that never entered large-scale standard service.
This example is even more distinctive because it retains its 25MM DUMMY marking, OL-0507 marking, steel tip, and feed link, making its original role much easier to understand when displayed.
About This Item
The photographed example has a tan/gold-colored finish with black 25MM DUMMY lettering. The OL-0507 marking is lighter and more worn but remains visible on the body.
The round retains its steel nose and one steel ammunition link.
The surface may show scratches, finish wear, oxidation, discoloration, faded markings, handling marks, and other signs of developmental use or long-term storage.
This listing is for one 25x59mm dummy cartridge with one link. The XM307 weapon, ammunition can, additional links, live ammunition, XM109 rifle, and other accessories are not included.
Ideal For
- XM307 ACSW collections
- Experimental U.S. ordnance collections
- 25x59mm ammunition displays
- Crew-served weapon collections
- Prototype ammunition collections
- General Dynamics weapons-development displays
- Modern U.S. military history collections
- Linked-ammunition collections
- Military museums
- Technical-reference collections
- Educational displays
Approx length 4.5", Approx width 2.5", Approx height 1, Approx weight .4 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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