Here is a good up close video of the sound. Sounds to me like an AK-47.
You may have to click the speaker on the video to hear it.
https://twitter.com/CollinRugg/status/914737490786783232
That’s actually not that good. The phone microphone is clipping the shots pretty badly due to the sound pressure levels at that distance and angle - there are other videos where you can hear the firing better since the microphone isn’t clipping.
https://twitter.com/bryannaguilar/status/914739214553686016
That’s .30cal fire.
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.