[dasm]

As you said, we have a little bubble on guns & ammo in the US right now.

Basic NATO 5.56 - ie, cheap enough for practice or poorly equipped grunts - is probably ~$0.30/round. However, it doesn't specify the caliber or load.

Loads designed for combat and not practice - like armor piercing, barrier penetration, soft target performance, precision, short barrel optimized, etc. - could be ~2-7x more expensive, and more indicative of a serious organizational problem.

Small arms calibers could include .50BMG, which is also a much larger cost & problem.