[Oblongata]

"You would think that this particular problem would have been discovered in the early stages of testing. However, switching from 6.8 mm to 5.56mm to save a few ouncues is a big mistake."

True it only saves a few ounces on the weapon itself. But a soldier also has to carry a load of ammunition. It's the difference between carrying 200 rnds of 6.8 compared to maybe 300 rnds of 5.56 of the same weight. That's where the advantage lies in going to a smaller caliber.

[Travis McGee]

The extra ammo argument worked in the jungle, with long foot patrols and spotty resupply. But in mounted and dismounted desert/urban warfare, carrying a multi day load of ammo isn't the deciding factor: stopping power and obstacle penetration are paramount.

[Atlas Sneezed]

True it only saves a few ounces on the weapon itself. But a soldier also has to carry a load of ammunition. It's the difference between carrying 200 rnds of 6.8 compared to maybe 300 rnds of 5.56 of the same weight. That's where the advantage lies in going to a smaller caliber.

---

The enemy is 500 yards away, armed with AK-47s. Would you rather 300 rounds of 223, or 200 of 6.8?

[SauronOfMordor]

It's the difference between carrying 200 rnds of 6.8 compared to maybe 300 rnds of 5.56 of the same weight.

Hey, for the weight of my 10-round mag of .45, I could carry several mags of .22, but I'll still keep my heavy .45, thank you very much

The grunt would much rather have 200 rounds of ammo that has a high probability of one-shot-stop at 500 yards, versus 300 rounds of ammo that has less than half the kinetic energy of .308, and loses half of that by the time it gets to 300 yards