I spent part of the day helping a friend try out a new design

That's Oren*, and the shiny can on the end of the barrel is the prototype of the suppressor design he's worked out. The expression is due to asking the dog what the hell it's doing(no, it did not pee on my leg). It(the can, not the dog) weighs a touch over six ounces, and it works.

As in, with subsonic ammo, the shot itself was a mild 'tick', much quieter than the sound of the bullet striking the target and backstop fifteen yards away; downright impressive. Yes, I want one when he's able to start producing them.

So the day was spent trying this out, talking and helping him take care of some things. Time well spent, I'd say.

*Had a question in comments, thought I'd add this: he's a NFA-licensed gunsmith(link above and on the sidebar), and yes, he had the license before he even put pen to paper