I've built a few that are very similar. I've gone to using used conveyor belt to hang the target though. It's amazing how easy it is to hit that chain, and then you get to take a hike to scab it back together, and you get back to your shooting position...settle in, catch your breath, and bam! Got it again! Kinda takes the fun out of it. On the positive side, you get to see how you can shoot when you've just hiked a quarter mile each way...twice.