Newbie question, which has worst muzzle blast?

AR/M4 AR General Discussion
1

A M4 carbine with a 14.5 inch barrel in 5.56x45 NATO, a 20 inch barrel M16 firing the same round or an AK-47 firing 7.62x39?

Which has more echo and can be heard farther away/louder from a dsitance?

2

AaronH and his other troll account CheckMyBrain are now gone.