M4 5.56 Upper Receiver Groups - M4 LE6921 Upper Group 14.5in With BCG And Sights
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Overview
The Colt M4 LE6921 Upper Receiver Group is a complete assembly designed for AR-15 platforms, featuring a 21.0-inch barrel chambered in 5.56 NATO. This upper provides a reliable and accurate shooting experience, making it suitable for various applications, including tactical use and competitive shooting. Builders often integrate this upper into mid-length or designated marksman rifle builds due to its longer barrel length, which enhances precision and effective range.
Specifications
M4 5.56 Upper Receiver Groups - M4 LE6921 Upper Group 14.5in With BCG And Sights
Available Merchants(4)
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Price Alert
Build history on GunPartPicker
Builders on GunPartPicker first added the Colt M4 5.56 Upper Receiver Groups - M4 LE6921 Upper Group 14.5in With BCG And Sights to a build in March 2026.
It was hard to find in September 2026, in stock on only 1 of the 26 days we checked, and today only Optics Planet has it in stock. It dipped to $652.61 at BattleHawk Armory for a stretch in September 2026, well under its usual $853.85, so sales do come around. Buying today, the lowest price is $775.99 at Optics Planet, above September's low of $652.61, so a better deal may come back.
Updated · from real builds on GunPartPicker · Prices checked · refreshed daily across 37 retailers
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