I bought one of the Drozd, Russian guns about 4 years ago, it works, I can't remember it ever malfunctioning, and as soon as let someone shoot it, it just " where did you get it? and where can I get one " now for the warning, these things are accurate enough, you need to be cool about your bb trap, for years I have used old towels, doubled over hung on wooden rods in a card board box, with usually 3 rods, that is the thickness of at least 6 towels, never been a problem, until you shoot full auto, with something, that at bb gun distance, keeps penetrating the same spot, I have made it rip through all the towels and out the back of the box. If you own a Drozd, there are some guys out there selling replacement circuit boards, that up it to 1200 rpm.
I have it in storage, but need to get it out and take pictures, I have a BB gun trap that is furniture, made in Georgia in the 50's and is mediterranian in design cabinet, open the doors and inside is a tiger striped spongy cloth, with a black aiming circle, front lighted and as you shoot the target, it drops the BB's into the lower drawer to reuse. It is a real piece of history, custom made for some well to do in the past, how I'm come up with this weird stuff. But if you walked in, you would never believe what it is, it even has a suction fan, that I can only guess is to make the cloth move.