Competition for a new carbine is heating up — and the big dog just entered the fight.

Colt officially unveiled its CM901 at the 2010 Association of the U.S. Army Convention and Exposition, held Oct. 25-27 in Washington, D.C.

Countless soldiers lined up to find out what this new weapon is. The answer: Just about anything you want it to be.

The CM901 boasts a universal 7.62mm lower receiver and multiple barrel lengths — a 10.3-inch for close-quarter battle, a 13-inch that is accurate at 500 meters, a 16-inch heavy barrel that is accurate to 700 meters and even 18- and 20-inch barrels if you want. A shooter can switch barrels with the push of two buttons — it takes longer to explain it than do it.

I'm guessing it's something else we can't own in MA.