Maybe. small microphones can miss portions of sound spectrum?
The only times I've heard full-auto AK (7.62x39) it was harsher, and heavier "crack-crack-crack-crack". Made my hair stand on end.
All good points and I know what you mean with the “crack-crack-crack” sound.
Phone-grade microphones tend to “clip” or miss loud sounds and simply record a pop-like noise when they hit their limits. Check out video of action cameras carried by our troops in the Sandbox and listen to their microphones clip when rifles or MGs are fired at close range. These microphones need to be at a greater distance to accurately record the sound of firearms discharges. Here’s one that was:
https://twitter.com/bryannaguilar/status/914739214553686016
Here listen to this AK-74 (American version of AK-47). Sounds the same.
https://www.youtube.com/watch?v=q72YfVJ5mwE