That is a much higher pressure than the 5.56 x 45 mm NATO round chambered by M4 carbines and M249 machine guns, which has a maximum chamber pressure of 62,000 pounds per square inch.

The M4 and M249 replacements will use a new type of ammunition as well, replacing the venerable 5.56 mm and 7.62 mm NATO standards. The Army hopes their new projectile will be superior.