Date: August 6, 2010
Picatinny develops lightweight weapons & ammo that cut weight in half
PICATINNY ARSENAL, N.J. - Soldiers may see the weight of small arms and
ammunition cut in half if a prototype M249 Squad Automatic Weapon (SAW) made
here is any indication of what their future holds.
Weapons and ammunition are proven to be two of the five heaviest items U.S.
troops carry. And considering the difficult terrains, high elevations and
fast-paced operations today's troops experience, the weight on their
shoulders is critical.
"The Army has been concerned about reducing Soldier load for years - this
isn't a new problem," said Kori Phillips, a systems management engineer for
the U.S. Armament Research, Development and Engineering Center (ARDEC) here.
"We've really put an emphasis on it with this project; there was a great
motivation for reducing weight."
The ARDEC team is near the final stages of designing and testing a
lightweight SAW that fires a special type of lightweight ammunition, called
"cased telescoped" ammo.
Cased telescoped ammo features a thin, plastic casing instead of a
traditional brass shell. One plastic case alone weighs 40 percent less than
its brass counterpart.
When loaded with 600 rounds of cased telescoped ammo, the new SAW system is
16 pounds lighter than a traditional SAW loaded with the same amount of
standard, brass-cased ammo.
"The cased telescoped ammo still provides the same muzzle velocity, range
and accuracy as the brass-cased ammo," Phillips said. "We're not sacrificing
lethality for weight; the plastic case does the same job."
Another benefit of the cased telescoped SAW is improved reliability, due to
a rotating chamber design.
"We've avoided the common problem of failure to feed and failure to eject,"
Phillips said. "In the current SAW system, that's where you primarily have
failures and malfunctions."
"It has a unique chamber design. The cartridge goes straight through from
feed to eject," Phillips said. "With a regular SAW, or M249, the chamber and
barrel is one piece. But in this new light machine gun, the chamber rotates
back and forth. The system works in a cyclical pattern, so you're not
interfering with your own system."
The lightweight SAW system has been under development for the last six years
and is ready to hit the range for a military utility assessment next summer
at Fort Benning, Ga.
So far, the ARDEC team, along with contractor AAI Corporation, has built
three lightweight SAWs and has test-fired more than 10,000 rounds of cased
telescoped ammunition. They plan to build seven more guns and produce
100,000 more rounds in time for the utility assessment.
ARDEC is also developing a lightweight rifle that fires cased telescoped
ammunition. This rifle is the same overall weight and length as a standard
M4, but because of the modified design, there is a four-inch gain in barrel
When loaded with cased telescoped ammo, this system weighs 40 percent less
than an M4 loaded with standard ammo.
Also under development is even lighter ammunition that promises to cut
weight by 50 percent and reduce volume by 40 percent, called caseless
telescoped ammunition. This round features a solid propellant body that
burns completely when the round is fired.
Essentially, the case itself is the fuel.
With caseless ammo, there is no need for the weapon to eject a case after
firing, which virtually eliminates weapon lock-up.
"There is so much more to consider when developing caseless ammunition,"
Phillips said. "We are currently redesigning it for cost purposes, but
obviously our primary concerns are the ballistics, the reliability and the
The team has built one caseless telescoped weapon and shot about 500
caseless rounds, but they have since had to go back and alter the design.