It does not blow up, and it does not blow open even though there is no locking of the breech.
The barrel is chamberless, overbored and that helps keep the pressures relatively low. The bore is about the same diameter as the outside of the shell.
A detailed observations shows the gun recoils as unit, both barrel and shroud tube recoil together. Which kind of casts doubts about the shell in a conventional shotgun delivering a hammer blow to the breech face etc by itself. Such guns, crude as they are, challenge orthodoxy on shotgun action strength.
As to blowing up in time. There are such crude guns that have been used hard for years and have not blown up.
