The KAK Industry 9mm Carbine Buffer Tube Kit (brand part number AR15-KT-005) includes everything needed for the receiver extension on a 9mm AR-15 carbine or pistol in one package. The kit centers on a Mil-Spec diameter, hard-coat anodized buffer tube, paired with a music wire carbine buffer spring and a 9mm-specific buffer weighing 5.4 ounces, tuned for the shorter travel and different recoil impulse of a blowback 9mm action compared to a gas-impingement 5.56 build. A Mil-Spec castle nut and end plate round out the kit.

Key Specifications

• Includes a Mil-Spec diameter buffer tube, hard-coat anodized.
• Includes a music wire carbine buffer spring.
• Includes a 9mm-specific buffer weighing 5.4 ounces.
• Includes a Mil-Spec castle nut.
• Includes a Mil-Spec end plate.
• Built specifically for 9mm AR-15 carbine or pistol builds.

Frequently Asked Questions

What’s included in this kit? It includes a Mil-Spec buffer tube, a music wire carbine buffer spring, a 9mm-specific 5.4-ounce buffer, a Mil-Spec castle nut, and a Mil-Spec end plate.

Why does 9mm need a different buffer than 5.56? A 9mm AR operates on straight blowback rather than gas impingement, so it needs a buffer weight and spring tuned specifically for that different recoil impulse.

Buy the KAK Industry AR-15 9mm Carbine Buffer Tube Kit

Complete your 9mm AR build’s receiver extension in one kit. Order the KAK buffer tube kit from our AR buffer system lineup, shipped fast from our Lubbock, Texas gun shop.