The U.S. Army's chief of staff told Congress the M4 Carbine's 5.56mm round can't penetrate modern enemy body armor plates and believes Infantry units need a more powerful rifle than the M4.

The U.S. Army's chief of staff revealed Thursday the M4 Carbine's 5.56mm round can't penetrate modern enemy body armor plates and plans to arm infantry units with rifles chambered for a more ...

The U.S. Army has issued a solicitation for a new, more powerful rifle that would replace the M4 carbine ... forces and infantry to penetrate body armor using existing ammunition." ...