Wilson Combat has developed a new cartridge that shoehorns a .30 caliber projectile into the AR-15. The 7.62×40 WT is a low recoil cartridge that exceeds the energy of the 7.62×39. Wilson Combat sees this as a versatile do-all of a cartridge that is suited for hunting and tactical applications.
It will be able to utilize a wide variety of the .30 caliber projectiles that are already on the market so reloaders should have no problem working up a pet load. The dimensions of the 7.62×40 WT will allow it to work with standard AR-15 magazines but some modifications may be required for better reliability.
You can read more about the 7.62x40WT project on the Wilson Combat website.