PROGRESS: Marines Testing Polymer Solutions to Cut Ammo Weight.

“We have to have lighter equipment,” Williford said, adding that the service is interested in using “polymer magazines, polymer rounds” and other polymer products to reduce ammunition weight.

The Marines have tested polymer-cased .50 caliber ammunition, but companies also make polymer ammunition pallets that offer significant weight reduction.

“On a .50-caliber pallet, we think we can save 1,000 pounds per pallet,” Williford said.

The U.S. Army has had a strong interest in reducing the weight of ammunition for a decade. The service has invested in the Lightweight Small Arms Technology program, which has produced a matured lightweight squad automatic weapon that is about half the weight of a 17-pound M249 squad automatic weapon.

I wonder if lighter rounds would be easier on the barrels as well as on the shooters.