The Army has revealed the weapon intended to replace the M4 carbine in front-line combat units.

The branch announced a 10-year, $20.4- million contract to Sig Sauer to produce two weapons it's calling the next-generation squad weapons at the end of April, according to a U.S. Army Public Affairs press release.

The weapons are the XM5 rifle and the XM250 automatic rifle. The former is intended for individual soldiers, and the latter is intended as a replacement for squad automatic weapons like the M249 light machine gun.

The weapons are being supplied to combat arms across the branch, with the branch planning on eventual widespread distribution. If the weapon is adopted across the Army, it would be the most dramatic change to the branch's standard weapon since the Vietnam War.

The M16 became the first assault rifle in US military use during that conflict, with the M4 carbine entering service as a shortened version of the rifle in the following decades.

The two weapons will fire a bigger bullet than their predecessors. Both are chambered for 6.8-millimeter rounds, rather than the 5.56 of the M4 and M249.

The new round is thought to be more lethal against a foe who is wearing body armor.

The military is gradually retooling for more conventional wars against state opponents, as opposed to the Global War on Terror against irregular Islamic terrorist forces.

The weapon has some visual similarities to the AR family of weapons used by both American civilians and service members, and some crucial differences.

The rifle has a charging handle like the AR-15, but its bolt catch is different.

"Both weapons provide significant capability improvements in accuracy, range and overall lethality," said the Army's statement in announcing the contract.

"They are lightweight, fire more lethal ammunition, mitigate recoil, provide improved barrel performance, and include integrated muzzle sound and flash reduction."

The weapons are designed for use with the XM157 Fire Control system, a tool that will integrate a variable optic, a laser rangefinder and a ballistic calculator.

Widespread adoption of the XM5 rifle isn't assured at this stage of its development, with the performance of the weapon likely to determine whether it becomes the Army's standard-issue rifle.

Colonel Scott Madore, who oversaw testing of the XM5 against competing rifles, said that service members tested the weapon for 20,000 hours to gauge its utility.

There's no indication that a civilian version of the XM5 is in commercial development, although it's likely a semi-automatic version will end up in gun stores if the rifle proves effective and reliable.

This article appeared originally on The Western Journal.