I may be wrong but there seems to be a lot of sound from the chamber when it is in the box stand.
That's what I noticed too. Port Pop is more commonly discussed when talking about suppressed use, as the shot noise at the port can be worse than at the muzzle, but the port is loud even unsuppressed when compared to a closed-breech rifle. If that port is pointed at the nearby wall of a box stand or another human's head a couple feet away, there is going to be more noise noticed than with a bolt gun. Been there before with both scenarios.
