M4-L89 5.56x45 NATO Assembled Upper Receiver - M4-L89 5.56x45 NATO 13.9''''BBL 13.75'''' L89 Rail W/Asr
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Sons of Liberty Gun Works
Overview
The M4-L89 5.56x45 NATO Assembled Upper Receiver is a complete upper designed for the AR-15 platform, featuring a 13.9-inch barrel that balances maneuverability with effective range. With a standard M4 receiver type and a thread pitch of 1/2x28, this upper is compatible with a wide range of muzzle devices and accessories, making it a versatile choice for builders. This configuration is often utilized in compact builds tailored for tactical applications or close-quarters engagements.
Specifications
M4-L89 5.56x45 NATO Assembled Upper Receiver - M4-L89 5.56x45 NATO 13.9''''BBL 13.75'''' L89 Rail W/Asr
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Stock Alert
Price and stock
The Sons of Liberty Gun Works M4-L89 5.56x45 NATO Assembled Upper Receiver - M4-L89 5.56x45 NATO 13.9''''BBL 13.75'''' L89 Rail W/Asr was out of stock everywhere we track for all of September 2026, and today the one retailer we track is out of stock. Listed prices start at $1,116.25 at Brownells for when it comes back.
Prices checked · refreshed daily across 37 retailers
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