The 400m and 600m ranges for Afghan ambushes seems to originate from the max effective range of the PG / MG they are using while allowing them to break contact after the engagement. Their fire is not what we would consider particularly accurate, but in most ambushes the killzone is restrictive and so it funnels the fire any way.

Reasons why their fire is in accurate - I have found in Astan particularly the men have horrible eyesight. They are malnourished from a very young age and develop cataracts early. Few have glasses. Also their is a primitive belief that Allah will guide their bullets, so much so that they feel aiming is questioning his omnipotence. Broad generalities - but then again that is what we are talking in.

Given that we generally want to kill the enemy and avoid over-kill as a principle - why would we not improve the effectiveness of rifles? The argument should be a cost - benefit one. It seems here to have devolved into one about whether we should just call CAS or roll up in our IFV.

If the individual soldier can be made much more lethal through a series of improvements (SA, survivability, ballistics, etc.) and the cost is worth the gain (mobility, financial, etc.) why would one not improve the soldier?

5.56mm has its benefits, soldier's today are not impressed with them (claims the paper [me too by the way]). Ballistics have vastly improved since the 5.56mm's inception and adoption. The Army in general does not believe the gain is worth the cost.

What the hell does a Laotian machine gun have to do with it?!

Yes, give the infantryman a better bullet. No do not adopt a radically different weapon now unless it provides x percentage of benefit over the current platform (think pulse rifle). Hell, improve the artillery and CAS and everything else too.

Also, where is the cost/gain argument with Javelin vs Dragon and Copperhead vs Dumb Hellfire and 155mm vs Excalibur? Is it just me or does it sound as if the Acquisition guys never fought as Infantry?