Craptacular is exactly right on the Tec-9. My cousin had one, years ago. We went and shot it out back at the grandparent's farm. I swear rounds left the barrel at about a 20 degree angle. Couldn't hit squat with it, and I'm normally in the black immediately with a new pistol.
My friend's dad died, and Rod (my friend) inherited his guns. He had several, all flashy-looking, all POSs. Even worse than the Tec was the .22 Scorpion -- a scale model of a Czech submachine gun, with a banana clip full of .22LR.
I was the first to fire the Scorpion. I checked everything, chambered the first round and squeezed. BRRRRAP! Out came three rounds. The range monitors on the other side of the glass popped up like jack-in-boxes. I hastily tried to gesture "dude, not my gun."
Thinking that it might just be me, that it might have a hair trigger and I might have twitched, I cleared the jammed round and tried again. BRRRRAP! At that point, the range monitors came through the door and I explained in person that my friend had just inherited these guns, we'd never fired them before, and yes, sir, of course I'll clear, unload and put this thing away and never, ever bring it the hell in here again.
I found out much later that there was a "recall" (more likely intended as an advertisement) of the Scorpion, because it could -- through normal wear and tear, with or without owner intervention -- become fully automatic. I choose to believe that Rod's dad didn't intentionally modify it. The only reason I got three-round bursts is that three rounds was the most it would fire without jamming.
Rod sold all of his dad's guns and used the money to get an H&K USP 9. Smartest move he ever made.
Of course, with an accurate gun, we found another way to anger the range monitors. Michael, who usually joined us at the range, had read that Mossad agents used 3x5 index cards as practice targets. We brought a pack of index cards, because (a) it was cool, and (2) they're much cheaper than regulation targets or silhouettes.
Problem is, with a target that small, we kept picking off the clothespins. The range monitor said that the next time we came back -- in a tone of voice that implied that we shouldn't, ever -- we should bring a roll of tape for the cards.