▁am mun ition ▁out ▁to ▁a ▁visible ▁range ▁of ▁ 8 0 0 ▁meters ▁or ▁more , ▁be ▁capable ▁of ▁accurate ▁high - volume ▁sust ained ▁fire , ▁and ▁be ▁l ighter ▁and ▁more ▁reliable ▁than ▁the ▁M 6 0 . ▁Initial ly ▁the ▁cont enders ▁were ▁built ▁around ▁a ▁new ▁intermediate ▁cart ridge , ▁but ▁the ▁problems ▁with ▁appro val ▁for ▁a ▁new ▁third ▁American - back ed ▁standard ▁NAT O ▁cart ridge ▁forced ▁its ▁abandon ment . ▁The ▁program ▁then ▁selected ▁between ▁the ▁control ▁group ▁weapons : ▁the ▁F N ▁Min imi ▁( X M 2 4 9 ) ▁and ▁He ck ler ▁& ▁Koch ▁H K ▁ 2 3 ▁( X M 2 6 2 ) ▁chamber ed ▁for ▁the ▁improved ▁ 5 . 5 6 mm ▁SS 1 0 9 ▁round . ▁The ▁F N ▁Min imi ▁was ▁adopted ▁as ▁the ▁M 2 4 9 ▁because ▁it ▁could ▁option ally ▁fire ▁from ▁mag az ines ▁from ▁an ▁integral ▁magazine ▁port ▁rather ▁than ▁requiring ▁an ▁exchange ▁of ▁parts ▁in ▁the ▁field ▁like ▁the ▁H K 2 3 . ▁▁▁▁▁▁▁▁▁ ▁The ▁Infantry ▁Autom atic ▁R if le ▁program ▁was ▁launched ▁by ▁the ▁United ▁States ▁Marine ▁Corps ▁in ▁ 2 0 0 5 . ▁Its ▁task ▁was ▁to ▁find ▁a ▁replacement ▁for ▁the ▁heavy ▁and ▁cum bers ome ▁M 2 4 9 ▁SA W ▁that ▁was ▁serving ▁as ▁the ▁Squad ▁Autom atic ▁weapon ▁in ▁a ▁fire team ▁at ▁the ▁time . ▁Two ▁of ▁the ▁weapons ▁in ▁the ▁competition ▁were ▁the ▁F N