If they are blanks, and there is no projectile, how did it turn a dummy into pink mist? How did it cut down bamboo trees?
Something doesn’t add up - it’s not the compression wave doing that damage.
That is because there “is” a “projectile”. The wadding plug acts as a projectile for short distances out from the firearm muzzle. It is very light and loses velocity very quickly, but it CAN be deadly if you stand in the wrong place. Even the expanding gas from the muzzle is dangerous if one is too close. Neither, of course, compares to a lead, bismuth, or copper bullet or buckshot...but “I” would not put myself in the active zone.