That pic brings back bad memories..
I got put on the bench for about a week after using one of those. Though not in a traditional manner.
I got asked to assist state P&P on an offender check or something (been so long ago I don't remember). But anyways the Parole Officer was this gal that was quite frankly oblivious about how dangerous some of these guys were and the dude she was dealing with in particular. He had one of those black powder pistols just like the one shown. I asked about it and she told me that in her mind it was not a real gun and was harmless
OK Lady...
Anyways, ol' Waingro was sketched out about something in his place. Fortunately, the gun wasn't loaded but it was obvious that he didn't want us there and would not stay still/stay seated. I told him a few times to park his ass on a chair and stay there. Long story short he eventually made a grab for a couple of kitchen knives that P&P Officer Clueless had let him work his way over towards on the countertop by the sink. He was leaning over the counter and was reaching with one hand and propping himself with the other for balance. Her back was to him and down the narrow little hall and not paying any attention to any of this..
Not wanting to get into a wrestling match over a knife in a confined space and not wanting to throw shots I picked up the black powder pistol by the barrel and smacked his hand that was on the counter pretty hard and he fell onto the counter and I put him in cuffs quickly while he was howling. It all happened in seconds and P&P had no clue what actually happened until I explained it.
Ends up the bones in the hand are a bit delicate, and I whacked him a bit hard. They broke. I sat out for the rest of the week on a use of force review while the brass determined my fate. I ended up getting cleared but what a pain in the ass.
Every time I see one of those things I think about it.