A yearlong effort between Remington and the military may have produced a replacement for the 5.56mm NATO (.223 Remington) rifle round. The new 6.8x43mm is built on the old .30 Remington case shortened to 43mm and necked down to take .277- diameter (.270-caliber) bullets. With the exception of bullet diameter, the cartridge is almost identical in size to the 5.56mm NATO round and functions in all existing AR-15/M-16/M-4 systems via a new upper unit/barrel.
Although its military future is uncertain, it should be a hit in the civilian market. At 300 yards the energy is similar to a 100-grain .243 Win. load, making it a legitimate 250-yard deer round, with the proper bullet.