I do not agree at all that the 5.56mm is an adequate military cartridge or that the caliber of the weapon used by the infantry is irrelevant.

The number of rounds fired in a fight are directly proportional to the damage the average Soldier thinks he will inflict -- I'll guarantee you that those using a 5.56mm weapon will fire more than those using a 7.62x51. That has psychological and logistic impacts (and yes , I'm allowing for the difference between weapons that will fire full auto and those that will not. I never allowed people that worked for me to fire M16s on full auto -- and more than one kid got a Steel Helmet thrown into his back for forgetting. Yeah, I know that, too; Article 93, throw in 117 and 128 if you want to stack charges...).

I also strongly disagree with suppression as a tactic or technique, I know many studies and a lot of observers and combat experienced leaders say it works but most of those efforts have been against poorly trained troops. You go up against well trained troops and try to hold them in place with 'suppression' and you'll get a shock. Suppression doesn't work against good troop but accurate shots do.

Wilf said:
"No tactical actions have ever been consistently lost, or operations failed because troops were using 5.56mm. Lots of armies using 5.56mm have no complaints."
I'll grant the operations not lost is probably correct but I'm not at all sure you're correct on tactical actions, even with the caveat you added, 'consistently.'

Not the question -- question is how many people have been killed unnecessarily due to an inadequate round failing to drop an opponent? You can start by looking at the PPSh 41 / 43 carriers...

(Acknowledging the Finns did better with their KP31s, partly a function of the Finns, partly the woods, partly a bigger caliber... )

Then look at US M1 / M2 Carbines used by the US, the UK and others in WW II -- then 5.56 in Viet Nam and in Afghansitan.

Size does make a difference. (so do terrain and vegetation, 5.56 will deflect on many leaf hits; the 7.62x39 rarely does that)