On pirate there is a thread about it, I think it may even be linked in this thread, but a guy built an exocage using pipe and a HF bender (if i remember correctly) and flopped it on video. The cage flexed a bunch and contacted the body a little bit when he did it. You know you guys can get heaver pipe than just schedule 40. Just throwing it out there.
Yes, but sched 40 is more readily available and cheaper. RUGER has a sched 40 cage, and I've seen him lay it over onto a rock HARD, landed right on the cage, and it didn't move a bit.
The material of the cage isn't the only factor, also the quality and cleanliness of the welds, # of connection points to the frame, and proper triangulation of the cage.