The MK 46 MOD 1 is the USSOCOM variant of the M249 with improved receiver pins, a feed tray with retention pawls and a vented handguard with MIL-STD 1913 rails at the 3, 6, and 9 o’-clock positions. It has an enhanced heat shield design and heat-resistant carry sling extension to help improve sustained fire performance and operator handling, and a carry handle mounted directly to the barrel to speed barrel changes. One spare barrel is included.