LBE Unlimited Carbine Length Buffer, Fits AR-10 308 ARBF308C The LBE .308 Carbine Recoil Buffer is for use with AR-10" LR-308 and SR-25 based platforms with a Carbine Buffer Tube. This is a drop in part with no modifications needed. LBE Unlimited is a leading producer of US Made gun parts and accessories. Weight: 3.8 oz.