FM Products PCC 9mm Heavy Buffer 6.5 oz w/ .308 Carbine Recoil Spring Black. The 9mm buffer created by Foxtrot Mike Products is designed for all 9mm blow-back operated pistols. With a 6.4 ounce (pistol) weight the Foxtrot Mike 9mm PCC Heavy Buffer has a 3.7 inch overall length and does not require a spacer or spacer remover. The addition of the extra-heavy duty .308 carbine recoil spring helps too since it is critical to the feeding and reliability of a blowback operated pistol caliber. The extra-heavy duty recoil spring found in this buffer kit is superior to any stock buffer because it has a proper spring selected specifically for the blowback operation of a blow back pistol. With the extra-heavy spring the FM Products 9mm buffer creates less felt recoil is a simple installation and you're good to go. Specifications for FM Products PCC 9mm Heavy Buffer 6.5 oz w/ .308 Carbine Recoil Spring: Manufacturer: FM Products Color: Black Gun Make: AR Platform Gun Model: AR-15 Length: 3.7 in Included Accessories: .308 Carbine Recoil Spring Condition: New Features of FM Products PCC 9mm Heavy Buffer 6.5 oz w/ .308 Carbine Recoil Spring Compatible with all blow-back 9mm upper receivers; Salt bath Nitride Melonite/QPQ finish gives lubricity and wear-resistance; Heavy 6.4 oz. (pistol) weight Comes with a .308 Carbine Recoil Spring to ensure proper function of your 9mm P.C.C. Build Package Contents: FM Products PCC 9mm Heavy Buffer 6.5 oz w/ .308 Carbine Recoil Spring What firearm models does the manufacturer say FM Products PCC 9mm Heavy Buffer 6.5 oz w/ .308 Carbine Recoil Spring is compatible with? The manufacturer says that FM Products PCC 9mm Heavy Buffer 6.5 oz w/ .308 Carbine Recoil Spring is compatible with AR-15FM Products FM9-HB-RS: PCC 9mm Heavy Buffer 6.5 oz w/ .308 Carbine Recoil Spring Black