Not really related but Spartan referring to it as a DI gun made me wonder, does anyone know what the technical name for the gas system in an AR-10/15 is? It isn't a DI as most people call it, that is where the gas just blows on the bolt carrier to push it back, whereas the Stoner system routes the gas tube into the bolt carrier which effectively becomes a piston pushing the bolt carrier backwards until the bolt unlocks and cycles the action.

Anyway, whatever the system is actually called, I agree that there is nothing wrong with picking that as a design. It has disadvantages, but it also has advantages. In my opinion it is much more likely that the US will carry on with the M4 PIP program than going for a totally new carbine.

I've only ever heard it referred to as direct impingement gas. If there's another name for it, I've no idea what it is.

In OSUT, the M-16A2s we trained with were simply referred to as "gas operated".

If I were Chief of Staff for the day, I wouldn't concentrate so much on a new carbine, but on a more effective round to use in it.

I have read Stoner's original patent application a while ago, and he made a point of saying that it wasn't a direct impingement design. I have heard a rather long winded name for it at some point that was something to do with gas expansion and the piston being in line with the bore, but can't seem to find it now.

"Gas operated" is broad terminology, though. An M16, an AK, and a Gewehr 41 are all technically gas-operated in spite of their different operating principles.

Even then, 5.56mm isn't exactly some pathetic whelp of a round that can barely even punch a hole through a Middle Eastern insurgent. The round's been used for ages and on many different targets by people in many countries for many years; the complaints have only recently started to come out in force. The problem doesn't seem to be with the 5.56x45mm cartridge itself, but rather the changes made when switching to the M16A2 standard.

Then again, I personally find the ban on expanding bullets in warfare to be inherently stupid. Police and hunters use it to ensure a quicker stopping and/or death of the target, so it would probably be MORE humane to use it against other people that you're trying to kill. It seems less about being "humane" and more about trying to make wounds look cleaner and help sanitize the concept of war.

Why did you think that same convention also banned serrated knives

Does anyone even abide by that one? I know both the M9 and OKC-3S bayonets used by the Army and Marines have partial serrations. The M11 EOD knife, which uses the same blade design as the M9, obviously would have those serrations, too.

AK bayonets have a saw blade as well. I don't know if that was ever an actual rule, more of a courtesy.