Wait a minute, if you say the legs are moving and the targets aren't then the targets are being muffled because they are connected to something else and not free hanging. It's just like hanging the fork from a piece of fishing line. If you hit the fork you're going to hear a ting. If you hold the fork with your fingers and hit it you're not going to hear that ting sound. So it's quite possible that there's some build up between where the target is hanging it's not allowing it to have enough area to allow that sound vibration. Saying that bar down real good to bare metal and put a white coat of primer on it and then try it and see what that works. If that's not the problem then you just need new metal. I know this one is kind of a stretch it's best to rule out everything before chucking out for more target
Same principle with the tuning fork if you hold the horseshoe part with your fingers it's not going to resonate and give you that sound frequency you're looking for. But if you hold the end where you're supposed to you get those frequencies. The same thing can happen to steal if there's something not allowing it to vibrate like it should. That could be dust, dirt, debris or anything like that that would cause it not to resonate.
Same principle with the tuning fork if you hold the horseshoe part with your fingers it's not going to resonate and give you that sound frequency you're looking for. But if you hold the end where you're supposed to you get those frequencies. The same thing can happen to steal if there's something not allowing it to vibrate like it should. That could be dust, dirt, debris or anything like that that would cause it not to resonate.