Lightweight Small Arms Technologies
The Lightweight Small Arms Technologies (LSAT) program is funded by the U.S. Joint Service Small Arms Program, with the goal of significantly reducing the weight of small arms and their ammunition. Following a series of military programs to investigate advances in small arms (SPIW, Future Rifle, ACR, OICW), the LSAT program is the US military's latest project to replace existing US small arms.
Source: Wikipedia — Lightweight Small Arms Technologies (CC BY-SA 4.0)