In my opinion, it's the most reliable in pretty much all situations, any terrains, and is easy to understand for an individual who has never handled or broken one down to clean. If I were in a combat situation, this would be my rifle of choice.
I've always been a fan of the G36. the problem is that someone who runs a rental range where one is available said HK ships them with an acceptable accuracy standard of 15 MOA - very hard to believe. Also heard that the sighting system isn't all that.
The problem with the AK-47 series is basically the 7.62x39 cartridge that feeds it. It's great if you want penetration but it does not cause very much soft tissue damage. Along those lines, the AK-74 utilizes a very effective muzzle brake and the much superior 5.45x39 - aka the 'poison bullet' coined by the Afghan mujahideen when they caught them from the Russians.
I can't remember but I think Russia was working on a platform that fired two round bursts that had a very low recoil impulse, but supposedly increased the lethality a LOT. Can't remember much else about it.
Also on the horizon is HK's replacement of the AR series upper. The AR's problem is that the direct blowback operation dumped a lot of soot in the chamber. The AK and G36 both utilize a piston to reduce the fouling (which makes them more reliable over time). My understanding is that the HK upper is going to utilize the piston as well, which might very well make the AR series the best assault rifle for the time being.
Not too familiar with the SIG 550 but it looks like a winner as well.
I've been a LEO now for 9 years in a high crime area and i've seen the damage the 7.62x39 round can make. I have literally seen it blow an individuals head in two parts and one officer told me how years earlier he had seen one round from an SKS take an adult males' arm off at the elbow.
But... what do you think of HKs m4 upper... replacing the direct blowback mechanism with the piston system. Why shit where you eat if you don't have to?
Various Articles I've collected named each of these as the all time best AR-
Beretta AR-70, FN FNC, Sig 551, Ruger Mini 14 GB/ AC556. I think the Stoner 63 too.
but arabs, russians, chechens, vietnamese, etc. aren't putting condoms or pantyhose over the action of the AKs are they? No knock on the AR platform, but if you have to break it down and clean it frequently in the field then hopefully you have others in your crew to provide watch. I'm not convinced that the reliability of the AK system is all due to sloppy tolerances, nor is all the rumored fouling of the AR series due to outdated powders, unchromed bbls, etc.
It will be interesting to see battelfield reports of the new M4 upper... I'm also not convinced that the OICW will catch on.