Condition: New Old Stock - unfired, taken off FROM NEW FIREARM (some units were test-fired by SIG) all NFA rules apply
For sale is a Sig Sauer MCX Rattler 5.56 upper assembly with a 5” barrel in unfired condition. This is a factory MCX upper, ideal for ultra-compact PDW builds using your MCX lower.
Product: Sig Sauer MCX Rattler Upper Assembly
Caliber: 5.56 NATO
Barrel length: 5"
Compatibility: MCX lower receivers or (standalone AR-15 upper with adapter)
Status: Factory complete upper ( with gas system, bolt carrier group, and charging handle included).
Ensure compliance with all NFA regulations if building into an SBR.
These are hard to find and no longer regularly produced by Sig.
