14.5x114mm

It's the bigger, of badder version of the 12.7x99mm, also known as the 50 cal.

Description
The .57 cal is a large caliber cartidge used in heavy machine guns and anti-materiel rifles. It's sheer weight and engery make it almost impractical to use for normal combat situations. However, it can go clean through armor and enegry shields in a single round. Though some very thick armors and shields can stop the round, the enegry it releases apon impact will not only knock the wind out of them, it will leave a mark. It is rare to see these in action during battle, but it is easy to tell when they have been used.

Users

 * Barrett DC99-S2