https://www.youtube.com/watch?v=1USoARAu7GQ

They don't now that Rob developed it!

Never mind .. they are playing with a brass case 12ga not a 12ga FH .. ya'll go pound them for lying

Those two boys are silly.
They are shooting Richard F's copper 726-gr slugs out of plastic hulls and having velocities with 300 fps spread,
930 fps to 1230 fps for the 3 shots I could watch before big boredom set in.
Their chronograph is just 4 or 5 feet from the muzzle,
and the front of the chrono rears up off the card table it is sitting on with each shot.
Truly an insult to robgunbuilder and Ed Hubel.