There are some good points and some very questionable ones.
Obviously shake is the mount.
There was some good intent that may or may not be in actality good. For example, the inclusion of a small powder chamber - in the spirit of Coehorn. The tube itself looked like it could have been at least a schedule 120 or so steel pipe - potentially very strong. And the welding MAY have been done right, certainly was referred to a "professional" if not a certified welder.
I couldn't see whether the fellow running from lighting the fuse was wearing eye or ear protection or not.
Unknown is what lay beyond the range - where one bowling ball ended up - assumed that it was free of people.
And, he had an interesting 'interpretation' of what was and was not legal - although he encouraged folks to check local laws.
There's more, but that's MY first impression.
