NEW HDD/EWA MK46A1 BOLT CARRIER/SLIDE. THIS IS THE LATEST UPGRADE FOR MK46, MK46A1 5.56X45 WEAPONRY, MUCH STRONGER THAN A M249 SLIDE THAT HAS THE OUTDATED CUTOUTS FOR MAGAZINE USE. THESE NEW SLIDES CAN BE USED ON THE OLDER M249 GUNS BUT CAN ONLY BE FED WITH A BELT, NO MAGS. (410)