I'm not saying the BAR was a godsend, but it actually fit the concept. The issue there was, as the problem with the M14 in the role, the full power cartridge lost controllability. The M16 version lacked a decent ammo feed system and overheated. I've got 20 years of reading the Gazette and a yearly article was a Gunner (CWO4) or group thereof bemoaning the lack of a real AR that would let the Marines actually move aggressively.
Will we ever find a
true Scotsman!
I apparently didn't describe doctrine correctly, you don't operate as a fire team, you pperate as a squad; you maneuver (fight) as fire teams, not as one big bunch or some amorphous split. There's no "static base of fire around the MG which allows the rifles to move who then provide a base of fire for the MG to move" which is out of stormtrooper tactics from late WWI. Instead, as I was taught at SOI and later at the Sgt's Course and utilized in all the training I ever participated in or conducted, a dynamic, constant maneuvering for advantage by the teams fluidly shifting responsibility for fire superiority, again, not constant FA "suppression", to enable the less heavily engaged teams to move agressively to put rounds on target, not just popping rounds to keep heads down.
[Despite going Army, I had to learn and implement USMC rifle squad tactics for some work projects, so I have some familiarity.]
Pretty much the same for US Army light infantry squads, but with more options. Of course, it is a bit more complex when the whole platoon's resources are figured into the mix.
You want to read about some truly funky infantry tactics, read, "The Bear Went Over The Mountain" about the USSR's tactics in their Afghan war (NOT the children's book). Left me with much head scratching like, "And they thought THAT would be effective?"
Anyway, belt feeds are not made for the assault, the belt is too vulnerable and the action too unwieldy compared to a rifle. Their sole advantage, sustained automatic fire, is not necessary most of the time, as your own comment points out.
Yep, belt feds are not
ideal for maneuvering rifle squads.
(I would point out that the 100 round bag we used in place of the 200 round drum was a big improvement for maneuver, both as to mass and vulnerability.)
Also, there is one teensy problem with dismissing the M249 in the infantry squad or team:
All data I have seen shows the SAW is the most lethal weapon in the infantry squad, both on offense and defense. From Army and USMC sources.
That is despite the M249's real flaws as you have described them.
I guess my question for the USMC is:
The M249 has a known/proved utility and lethality that doesn't completely mesh with USMC preferred theoretical doctrine and they are willing to throw it over for equipment that more closely approaches their theoretical doctrine without appreciating why the M249's is presently the most effective arm in the rifle squad. Especially given that a
"true scotsman" "true automatic rifle" has not ever been deployed.
I can understand hewing closely to religious doctrine. Where is the data demonstrating the effectiveness of trinitarianism vs arianism? But, hewing closely to military doctrine in the face of new developments or proved effectiveness smacks of doctrine for doctrine's sake or mere contrarianism ("We are NOT the US Army, thanks!")
Perhaps that is why they are keeping the SAW accessible, so as to hedge their bet. Worst case scenario, they have a fine high(er) sustained ROF DMR-type rifle for the rifleman to tote as the automatic rifleman picks up the M249 again.
That gave me as a PL:
10 Machine guns (Medic carried "Medical Insurance" 
)
10 MGs in a ~infantry/scout platoon. And I though MY unit liked MGs a-go-go at the platoon level.
So you guys functioned a bit like modern dragoons?*
Sounds like it. But, most mechanized light cavalry or infantry recon units in the Army since WWII have been of this flavor. I think the MP's have ripped many pages from the recon/cav playbook, which is a fine place to start.
One of the senior CONOPS guys at my company guys seems to try to turn every organization into a modified cavalry unit: heavy on the firepower & crew-served weapons with some sort of motorized component. I'm the guy who interjects, "You need more infantry. You gonna drive that <vehicle> into the <buildings/forest/paddies/mountainside>?"
there was one FA Battalion OPCON to each MP BDE.)
[borat]Very nice![/borat]
Spare barrels?
SPARE BARRELS?
Ha!
Here is a GPMG light enough to use as a SAW, with a barrel longevity of 20,000-30,000 rounds.
Spare barrels? AHAHAHA.
Yes, that truly is a squad automatic weapon. No mistaking it for an automatic rifle.
The barrel is somewhat heavier than that of the PKM, and has radial cooling ribs. This is enclosed in a steel jacket, which runs up to the muzzle to provide forced air cooling a-la Lewis machine gun of the World War I era. Cooling air enters the jacket through oval windows at the rear of the jacket, and exits at the muzzle.
Forced air cooling. Sweet.
The manufacturer says that the Pecheneg can fire 600 rounds in continuous sustained fire without any danger to the barrel.
Rate of fire ...............................................650 rds/min
Effective rate of fire ..............................250 rds/min
Sustained/effective ROF of 250 rounds/min without bbl changes is outstanding.
