M4 5.56 Complete Monolithic Upper Receiver Groups - M4 LE6945 Upper Group 10.3in With BCG And Sights
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Colt
Overview
The Colt M4 5.56 Complete Monolithic Upper Receiver Group features a 10.3-inch barrel optimized for the 5.56 NATO caliber, providing a compact and versatile option for AR-15 builds. As a complete assembly, it includes a bolt carrier group and sights, streamlining the installation process for builders looking to enhance their platform with a reliable upper receiver that maintains the familiar M4 style. This upper is commonly found in short-barreled rifle configurations and builds aimed at maneuverability and rapid handling.
Specifications
M4 5.56 Complete Monolithic Upper Receiver Groups - M4 LE6945 Upper Group 10.3in With BCG And Sights
Build history on GunPartPicker
Builders have been adding the Colt M4 5.56 Complete Monolithic Upper Receiver Groups - M4 LE6945 Upper Group 10.3in With BCG And Sights to their builds on GunPartPicker since March 2026. All time, it ranks #653 of the 1,705 upper receivers builders have added.
It was hard to find in September 2026, in stock on only 8 of the 22 days we checked, and today 2 of the 3 retailers we track have it in stock. It dipped to $1,073.78 at BattleHawk Armory for a stretch in September 2026, well under its usual $1,349.99, so sales do come around. Buying today, the lowest price is $1,073.78 at BattleHawk Armory, which matches the best price we saw in September.
Updated · from real builds on GunPartPicker · Prices checked · refreshed daily across 37 retailers
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Frequently Built With
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