There was some debate as to what this material was made of sometime ago on the forum. Well, I think I can end that debate now. We purchased a new stud gun to drive 1" studs and replaced an older model that was limited to 3/4". The guy was here today helping us get it all set up and running, so I asked him what the material was and he says that it is Aluminum and used for the same reasons that Al had stated during that friendly debate.

I appreciate someone asking that question in that thread, because now I've asked the question and had never really given it much thought before they asked that question.