The US Army has released a solicitation for a new 7.62mm infantry rifle to replace the M4. The Interim Combat Service Rifle program, known to be in the works since April of this year, would replace M4 Carbines in use with combat units with a new weapon in the 7.62x51mm caliber. The new solicitation requires companies to submit 7 weapons plus ancillaries for testing, and includes the promise of up to 8 Other Transaction Agreements (OTAs, non-contract transactions), leading to the eventual selection of 1 weapon for a contract of 50,000 units.Interesting. I'm not sure what the motivation for this project is, but it is interesting and pwill probably ignite the old caliber flame wars.The M16/M4 platform is a mature technology and is well regarded in many circles, but it seems that the body armor is an emerging technology and the Army wants something with more punch than can reliably be squeezed out of the 5.56mm.
At one point several years ago, I had opined that the perfect service rifle would be a platform that used 6mm ammo in the vein of the .243 Winchester. It would offer increased lethality over the 5.56, great ballistics, and lesser recoil than the 7.62mm.