Really useful educational materials. Sadly, the actual utility of these bullet hoses is limited to specific circumstances where multiple targets are within 5 yards and massed for rapid delivery of a large amount of hurt to achieve nominal effect.
For most purposes defensive semi-auto - and aimable - means are preferable. Still, these are relatively easy of manufacture, and when they're the right tool for the job, are hard to match in effectiveness for that specific utility.
Thanks!
Lots of options out there, if you have the tools,...
Today one may not need to clean up some rooms, but freedom demands this be available.
Evolution is magic.