Manning, ive never seen a Platoon of Automated Logistical Specialists clear a village, just sayin'. Grunts still win the war. Sustainment, Intelligence, Medical, and the rest of the Sustainment and Support in a Brigade Combat Team makes it possible for the grunts to do so. I dunno if you were ever in the Army, or if so, when you were its still legendary how bad Sustainment was when the divisions ran it with Divisional Units across the entire division, instead of embedding sustainment and support battalions in each Brigade Combat Team. If you're Cold War Army, you can probably remember it. When three to five weeks meant quite possibly never.
But really, this weapon is not that much lighter. A loaded M249 weighs 22 lbs. One of these things (which as far as I know doesn't even have an experimental model designation (XM for short, like the XM8 and XM29) weighs 12, and since they didnt say if that was its loaded weight or unloaded, Im going to be cynical and say they were giving unloaded weights, which to answer that, the M249 weighs 17. 10 lbs isnt exactly a game changer when you're already carrying another 15-40 lbs of crap.
As far as lightening the Soldier's load, we need a unified battery system, lighter armor which would preferably be flexible (you civilians have NO idea just how much of a bitch it is to get over a wall in Improved Outer Tactical Vests, and the Armor the British Army uses is even worse) and several other things like making the tactical radios lighter, encrypted, and able to interface with the higher nets and foreign nets. Its a real bitch being shot at in Afghanistan, knowing full well that someone has aircraft patrolling in your AO, but not being able to talk to them unless your unit happens to have a TACP either with you or within range and on your net.
This was a few years ago, and its been a pain in the Army's collective ass since Grenada, so hopefully they'll be fixing the radio issues sooner rather than later.
But honestly, what we really really need is a single type of battery for our electronic equipment, or at least a unified charging system. Battery technology as it stands sucks. I was a Squad Radio Telephone Operator, and with the Harris radios we used for the long range nets, you'd have to carry 4 or so spare batteries for a 3 day patrol.
But anyway, back to this weapon. Its simply too complicated, when it takes half a page on a tech website to describe the ammunition, and only the ammunition. Its simply too complicated. And I can virtually guarantee you that it isnt as reliable as an M249. It would be XM(insertrandomnumberhere) already if they figured it might be better.
If the weapon's complexity actually doesn't stop it, Army Politics will. The way that Ordnance Corps and Natick Soldier Systems Center/PEO Soldier picks weapons for units that aren't SOPMOD (about 93% of the Army) is based on reliability testing first. This is why SOPMOD units use all kinds of weird weapons, like the M110, the FN SCAR, etc. And also why we're still using M14 derivatives as our Medium range semi-automatic Marksman rifle because noone's ever developed anything better.
Anyway, If your weapon isnt as reliable as what its intended to replace, it wont go any further in the consideration process unless you can justify a new class of weapon, and after the Mk 19 Automatic Grenade Launcher and its perceived lack of usefulness at Flagpole, you're gonna be hard pressed to do so. Anyway, if its not a new weapons system you have to play the Army's game about replacing existing systems. Its the same reason the XM8 project was terminated, it simply never passed Phase I because it wasn't as reliable as an M16A2. They move onto functional testing after that. Its also why the M16 series probably won't be replaced anytime soon, unless its by a modification like the H&K 416/417 uppers for the M4 and M4A1.
And the reason Im replying instead of saying something directly is that Specialists may not be decisionmakers, but they're by and large the people actually working. I was a Specialist for nearly 3 years and was much more intelligent than a large number of Sergeants and virtually every commissioned Officer I ever met (Ironically the West Pointers were always the dumbest, ROTC officers weren't much better).
The only people on the whole better than Specialists as far as practical working knowledge in the Armed Forces goes are Chief Warrant Officers. When I made NCO finally, Id listen to the Specialists and CWOs the most when it came to actual work product matters. Administration stuff is mostly Sergeant's stuff but hell, I was only an E-5 and E-6, I didnt have much say in any of that. Some, but not much.
Privates are usually 18-20 years old, so they piss and moan most of the time and try to bullshit their way out of work, Sergeants are either really cool and down to earth or really bitter people who are mean for meanness' sake. Junior Officers think they own the world, Senior Officers think they know everything and DO own the orld. So really the only people with sense are the ones who fall through the cracks, Specialists, Sergeant First Classes, and Chief Warrant Officers specifically.