The Colt AR6721 Action Spring is a factory-spec replacement designed to keep your AR-15 Carbine or AR-15 Government Carbine running smoothly. Built to Colt’s standards for consistency and durability, this action spring helps maintain proper cycling and a clean, predictable recoil impulse in AR-15, AR-15/M4, and M16 pattern rifles.

Ideal for refreshing a well-used carbine or completing a quality build, this spring supports reliable function during training sessions, range days, and general recreational shooting. Its straightforward drop-in design makes installation simple for most AR-15 owners, while preserving the familiar feel and performance associated with Colt-pattern rifles. Shooters who value dependable operation and proven engineering will appreciate that this component follows the same design used in Colt’s respected AR platforms.

• Manufacturer: Colt
• Model: AR6721 Action Spring
• Type: AR-15 Action Spring
• Compatibility: AR-15 Carbine; AR-15 Government Carbine; AR-15, AR-15/M4, M16
• Shipping Weight: 0.068 kg
• Shipping Dimensions: 310 mm (L) x 56 mm (W) x 23 mm (H)