Barrett XM-109 25mm. Rifle - WOW
The XM-109 is based on the M-107 .50 Caliber semi-automatic rifle, but with a 25 mm receiver. It is designed to destroy light armor, and yet be light enough to be carried by a single sniper.
The old saying that "If the enemy is in range, so are you." just may not apply if you have one of these!
To read the full story, take a look over at Military.com.
Hat tip to Grampa Pinhead for the story!