It looks like it could be back to the future for the US Army, if Textron’s new carbine design is any indication of what’s to come. The company unveiled its latest prototype of a cased, telescoped ammunition-firing rifle at Modern Day Marine 2016 in Quantico, VA, on Tuesday. The rifle, which weighs 8.7 pounds unloaded and feeds from a 20-round magazine, is reported to fire a 123gr 6.5mm bullet at 3,000 ft/s, producing 3,350 J and rivaling the existing 7.62 NATO in energy. Military.com’s KitUp! reports:

Textron Systems unveiled its new 6.5mm case-telescoped carbine at Modern Day Marine 2016.

The weighted model represents Textron’s latest effort to develop a new age of infantry weapons that fire weight-saving, case-telescoped ammunition.

Textron has made significant advancements in this technology with its Light Weight Small Arms Technology, or LSAT – an Army funded program that has so far yielded working lightweight machine guns in both 5.56mm and 7.62mm.

The new 6.5 CS carbine emerged out of an intermediate caliber study Textron conducted in 2014, according to Ben Cole, project engineer.

Currently, the empty weight of the mock-up carbine is 8.7 pounds. A magazine loaded with 20 rounds of case-telescoped 6.5mm ammunition adds one pound. An M4A1 weighs 7.74 pounds empty and about 8.74 pounds with a loaded 30-round mag.

Case-telescoped ammunition is about 40-percent lighter when you compare it to the standard brass ammo in the same caliber, Cole said.

The 123 grain 6.5mm has a muzzle velocity of about 3,000 feet per second, Cole said.

Comparatively, the 62 grain bullet on the M855A1 has a muzzle velocity of 2,970 feet per second, according to U.S. Army data.

“If you take this 6.5mm bullet at our muzzle velocity, it’s 300 percent more down-range energy than the M855A1,” Cole said. “So for a minimal weight gain, you would have significantly more down-range lethality.”

Textron officials hope to have a working prototype to begin testing early next year, Cole said.

“We are trying to go after the next requirement for soldier rifles,” Cole said.

The rifle appears to be the latest variant of a weapon that had been shown off in a slideshow for Picatinny’s CTSAS program earlier this year, where it was quoted (at the time) as weighing 9.7lbs. Since no changes between the two weapons are apparent, it seems that 8.7lbs is the unloaded weight, and 9.7lbs is the loaded weight. We can also see that the muzzle performance of 123gr at 3,000 ft/s is consistent with the downrange energy at 1,200 meters of 300 ft-lbs displayed in the same slideshow, suggesting that this weapon also uses the 15.4 gram per shot 6.5mm ammunition shown there. This would mean magazine weight for this system is 146 grams, consistent with my estimates for the same.

Image source: kitup.military.com

I note that their loaded weight figures for the M4A1 Carbine appear to be for a fully loaded M4A1 with optic, PEQ, and other accessories. Unloaded and stripped, as the weight for Textron carbine seems to have been measured, an M4A1 weighs about 6.5 pounds.

123gr at 3,000 ft/s is extremely high performance for a weapon of this type, but a loaded (without accessories) weapon weight of 9.7 pounds is also very high, especially for a rifle that only holds 20 rounds in its magazine. Is the tradeoff in weight worth the extra performance? How would such a high performance round (assuming correspondingly high recoil) affect the shooter’s ability to put rounds on target quickly and accurately? It’s difficult to know, but it seems that this iteration of the Textron carbine is more M14 in weight and performance than M4 Carbine.

H/T poliorcetes, Military Guns & Ammunition forum