No offense but I can sure tell the difference between a .223 and the other two. The difference between the 270 and .308 is a lot harder to discern.
The report of a .223 versus a .308 is like comparing a .32ACP to a .357 mag in my view.
"The report of a .223 versus a .308 is like comparing a .32ACP to a .357 mag in my view." We were talking the sound of the bullets in flight as they pass nearby, not the initial muzzle sound. Shooter2.5 has experience with 223 & 308 rounds going by as a target tender.