So....the Russians saw our "less effective" round, and copied it with the 5.45x39 because....why?You may think the military rifle round upgrade is pointless Ajole but the 5.56 x 45 round was too big of a compromise for a main military rifle when we left 7.62 x 51. We should have went with a rifle round that had a caliber of 6.5 to 7 millimeter and had at least a 100 grain bullet that had a muzzle velocity of around 2,650 to 2,900 feet per second. The 5.56 bullet is too light and small and less effective. (Take note that I did not say it was an ineffective round.) Almost all intermediate rifle rounds beat 5.56 x 45 in putting hostiles out of a fight.
It wasn't a compromise. It was the target. And EVERYONE wanted to leave the x51 behind, but they couldn't because the US Army REMF brass insisted it be the MG ammo of choice. And then secretly developed a rifle for it. If the Brits had had their way, they would have had a 7.2 mm/.280, But the US thought it was too weak for MG's. Of course, that's the same US that insisted the GI rifle be X51, despite every test showing the other ammo...like, EVERY other ammo....to be better.
The .223 was used because the .222 Remington was on the shelf, it was easy to get the velocity desired, and parts like barrels and such were available. As development went on, they hurried and pushed and didn't want to slow things down by changing in mid stream...and besides, there was no need, in testing the round had it all. And it did well in the jungle too, BTW.
Then, on accuracy tests, you could get double the numbers of riflemen shooting expert, than with the .308. So...big bullets, some hits, or small bullets twice as many that hit the target, and 3 times as many in the load out?
Sorry. It's total and complete BS that the 5.56 wasn't good enough, and anyone that has looked at real military tactics...not these stupid patrols, not the police action BS, not convoy protection through enemy controlled areas, but the kind of war where you take and hold ground, and bring the pain to the enemy in large indiscriminate bombing and shelling operations designed to reduce the enemy to impotence, can see that we are asking the rifleman to do things he shouldn't be doing, and THAT is the problem, not the bullet.
So yes...if you insist on sending people out into no mans land like in WW1, it's good to get them a weapon that will work better.
But the BETTER answer is...stop sending people out there! It's pointless! It accomplishes nothing! And we've seen that and known that since Vietnam, but for some politically expedient BS reason...we keep doing it.
And the fact is, a bigger bullet in a shoulder fired rifle isn't going to help. They will just step up the IED's, use more mortars, rockets and such...and our guys will still be complaining they can't hit the bad guys as they are too far away.