I just skimmed through these threads. Some interesting thoughts on various topics here.
WRT the Aussie Peelback (which I believe was created by the Aussie SAS in Borneo or Vietnam, hence the name), those who think it's a waste of time are morons. Pure and simple. When people are shooting at you, you do not just run away, that is what gets your people killed. You and your mates put down boat loads of fire and toss several frags and smokes to supress the enemy so you can get the hell out of there. Rifle platoons are rarely if ever going to peelback. Small patrols however, are the majority of the time going to do that because they are just that, small. If you have not supressed the enemy then when you get up to run he will shoot your sorry ass. As another board member stated, there are many variations of it. To each their own. The only thing I will say is that if it's contact front (that includes front left and front right), then every member of the patrol should take a step off the trail left and right alternating so there is a corridor down the middle for the patrol members to run down. If it's contact front and you have the troops run down either the left or right side of the patrol and some bad guys pop up on the sides during the action, you will have a KIA from friendly fire. My section commander during my BMQ a few years ago taught the peelback this latter way, and when I tried to point out to him how that places undue risk to the patrol members I was quickly silenced. Being a recruit obviously I had no clue what I was talking about :
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Which leads me to my next point. Those statistics, such as, "US pers. expended XXX number of rounds for each enemy soldier killed." Think about it for a second. What is the majority of our fire used for days? Let's say it together class: supressive fire. So really I don't find it odd at all to have a section expend close to a thousand rounds trying to kill two guys in a trench.
WRT rifles that fire large calibre rounds (i.e. 7.62). Those are called battle rifles. Rifles such as the AR family of weapons, SA80, etc. are called assault rifles. Proper terminology is important for the sake of accurate debate. Yes, 7.62 does have better wounding characteristics than 5.56, but the ammunition is also heavier and bigger (so you cannot carry as much of it). And believe me, you need a lot of ammunition these days (for extended battles like in Somalia, 1993, or to suppress the enemies from time to time; try carrying 10-12 mags of 7.62) As well, battle rifles are typically heavier as well. Try putting on a PEQ-2, Surefire light, scope, etc. on an M14 and come tell me what it adds up to. I think you'll be pretty shocked, and if you aren't, well, you're glad to try humping that beast up and down a mountain for a day and tell me whether you want to stick with it or switch to an M4 or C7A2.
WRT full auto capability vs. 3rnd burst. I've also heard that 3rnd burst was stipulated due to the rate of expenditure of ammunition by US troops in the Vietnam war. It is, however, a capability which should not be in place on an assault rifle. Proper training and trigger control is what needs to be fostered, not an articial constraint. The 3rd burst mechanism in the M16A2 and M16A4 does not have a memory. If you fire a burst and you only have 2 rnds left in your magazine, then change mags and pull the trigger, your weapon will fire only 1 rnd from the newly loaded magazine to complete the burst cycle. Full auto is required to clear trenches still, in some OBUA situations, in the defensive, and to suppress the enemy in certain situations. Obviously you do not fire more than a 2-5 rnd burst from your rifle at ranges more than a few meters away. So to use the excuse that it is wholly inaccurate during long bursts at range as an argument that full auto capability isn't required is a tad foolish. There's a reason US SOF use the full auto capable M4A1 and 22 SAS has switched to the full auto capabile C8 SFW from the M16A2.
Finally, WRT bullpup weapons, the AR family of weapons has a casing deflector. Bullpup weapons have no such feature, and thus if you try to do a cross-shoulder transition with a bullpup weapon be prepared to eat a face full of brass and then get shot while you're dealing with that.