Actually, the second video helps a lot. They seem to be shooting at the tan building to the right when the camera looks around the corner. Watch the guy with the grey shirt and AK, hes shooting at the third floor of that building. Its also helps explain what the guy with the PKM is doing, suppressing the entire building.
I don't have sound, but if you guys are basing the caliber of the weapon on the sound, don't. Cameras and your speakers cannot reproduce the sound of gunfire accurately, 160db is off the chart for such things. Which is why a gun farther away could sound louder than one close by, as the closer one will be so load as to not register or be reproduced. If it was a heavy MG, it would have tore large chunks out of the wall, both to the left and right, not just pockmarks.
too close what ever it was , less than 50 meters
We can do an estimate for today for fun (as we don't really have the good numbers, it's purely for entertainment value).
Between 2002 and 2005 the GAO estimated a consumption of 6 000 000 000 small arm munition, and the US forces roughly killed 30 000 enemy (higher end estimation Afghanistan + Irak) in the same time-frame, that's 200k bullet by kill.
Now that include training ammo of course, but even if only 1% was use in combat that still mean 2 000 bullets by enemy...
And that's assuming that EVERY enemy was killed by small arm fire which is certainly not the case.
AFAIK there are no studies on enemy combat loss, but we can oppose it to the NATO combat loss studies that show that around 80% of the fatal injuries are made by explosions and shrapnel, and only 15 to 20% are bullet related. All that despite armor, kevlar, medics/casevac and fighting enemies mostly equipped with small arms and light support weapons (light mortars, RPG,...).
Assuming it's roughly the same for the enemy (20% dead by small arm fire), and I seriously doubt it is, that leave only 6 000 enemy dead from the bullets fired at them.
That's 10k bullets by enemy killed, assuming 99% of the small arm ammo was used in training.
One could also argue that the training is meant to kill the enemy when encountered and therefore should be included in the count, but the number ended up to be ridiculously huge (1M bullet per kill)...
Some might argue that in many ways, for modern Armies the Small Arm has simply become a protective item in many ways more akin in application to a psychological weapon than to say Swords of old...
The reasoning for this thought? In many instances it seems that small arms are simply to force the enemy back, suppress them and basically stop them engaging you before you bring in an actual system to do the real damage (Mortars, Artillery, Airpower)...
This is not to say that they do not kill and that particulary for Infantry who must close with and destroy the enemy, but it may seem often and perhaps even the majority of times actual doctrine is not relying upon them to do the work of killing nor as time goes by is there as much reliance upon said, closing and engaging the enemy on a personal level