Yeah as said above is true:
WASHINGTON (Army News Service, May 22, 2014) â€” A thicker barrel will absorb more heat in the new M4-A1 carbine, should a Soldier need to flip the selector to auto, according to Soldiers overseeing the new configuration now being added to the M4.
While shooting in the automatic mode is less efficient and not as accurate as firing in bursts, it has its place on the battlefield, explained Command Sgt. Maj. Doug Maddi, Program Executive Office Soldier, Fort Belvoir, Va.
â€œSoldiers need automatic capability while providing suppression fires during fire and movement,â€ he said, noting that Soldiers deployed to Afghanistan asked for that and are now getting it, an option absent in the M4, which only fired in semi-automatic and bursts. A new drop-in trigger allows the A1 to function with the automatic setting.
Maddi and others spoke May 21, during a media roundtable, marking the milestone of the first Army unit to receive the beefed-up carbines, 1st Infantry Division, out of Fort Riley, Kan.
The beefier weapon is not unknown to the Army. Soldiers in U.S. Special Operations Command have been using M4-A1s since 1994.
The tradeoff in weight and performance is something Soldiers gladly accept, Maddi said, noting that the M4-A1 weighs 7.74 pounds, compared to the M-4â€™s 7.46. The weight comparisons include the back-up iron sight, forward pistol grip, empty magazine and sling.
Another feature thatâ€™s new on the A1 is an ambidextrous selector lever, something thatâ€™s especially attractive to Maddi, who said heâ€™s a lefty who often gets left out when it comes to equipment design."