[E. Pluribus Unum]

If you listen to those bursts, they aren't from guns with bump stocks. Bump stocks are impossible to keep going in long, uninterrupted bursts. You might get three or four in a row, then another three or four, then a dozen.

Those bursts are from automatic rifles.

[TigerClaws]

Bump stocks are unreliable. No way those are from using bump stocks, which are also difficult to control. Was a heavier weapon and we haven’t seen a list yet of what they found inside his room.

[Pollster1]

Perhaps he practiced with his bump stocks, adjusted them, and tuned them to work more smoothly.