Luth-AR Heavy CAR Buffer Assy. You may also experience a reduction in felt recoil. The H1 contains 1 tungsten slug and 2 steel slugs in the buffer for a total weight of 3.8 oz or .25 lbs. Specifications for Luth-AR .223/5.56 H1 Carabine Buffer: Manufacturer: Luth-AR Gun Make: AR Platform Gun Model: AR-15 Weight: 3.8 oz Gun Type: Carbine Caliber: 5.56x45mm NATO .223 Remington Height: 3 in Package Contents: Luth-AR .223/5.56 H1 Carabine Buffer What firearm models does the manufacturer say Luth-AR .223/5.56 H1 Carabine Buffer is compatible with? The manufacturer says that Luth-AR .223/5.56 H1 Carabine Buffer is compatible with AR-15Luth-AR BS-11T: Heavy CAR Buffer Assy