it's not the gun itself that's the big deal, it's how it's used and interfaced with the landwarrior system, here's a cut & paste from my other post in a different thread
it's going to be one of the biggest advancements in infantry we've ever seen. what you've seen so far is just the start, these systems are bulky now, but these are just proto-type units. they are already 1/3 the original weight, and the computer is 1/2 the size. this system is unbelievable. imagine a squad leader able to issue orders real time by video. the soldier has one eye in the open and another on his HUD (like apache pilots). the leader could bring up an overhead map, and give waypoints and objectives on the fly, rather than having to have guys stop and get their maps and do readings etc.
the system will allow soldiers to see the enemy in pitch black, there is no place to hide from these things. one camera mounted in the scope direct feeds into the optic, to clear corners all the soldier does is point the rifle around the side and he can see everything, with no need to expose himself to enemy fire. enemy runs and hides behind a building? no problem, fire the cannon, when the round gets behind the building he detonates it.
this system is going to be one of the biggest life savers for soliders. from what ive seen it will be the ultimate system as far as use and safety is concerned. as the program develops the system will get lighter and smaller. and the cost is fantastic. excluding weapon they are estimated at about 15,000 a soldier. bring it on!