I'm not sure this truly classifies as a military rifle...but I'll put it here anyway.
I have had the privilege of being on the military base where this thing is tested. I was in a parking lot about 100 yards from the gun when they set it off one afternoon for a test firing. I didn't see much...but I sure felt it. It felt like I was hit in the chest by a hammer. There were some very tall spruce trees between me and the test range. Those trees bent to a 45* angle then immediately sprang back to upright when they set it off. It was certainly an experience I'll never forget. Ever hear a little kid say "do it again"....yeah...I'm like that kid.
Enjoy.....
redhawk
https://www.youtube.com/watch?v=58MmOpSm4LY