More Pneumatic Questions

Everyone did a good job of getting back to me last time about what to do for a socket retainer, so I figured I would try again.

In my last post, I had mentioned that I picked up a well used Chicago Pneumatic 1/2" impact gun to try with my new compressor. I just want to try and figure out what ratings this gun has, but I cant even figure out what model it is. No markings on it other than the CP logo. Is there an easy way to tell what model this thing is? Im specifically trying to figure out the torque ratings.

The reason I ask is that it worked great for the lug nuts on my car, but couldnt budge the rusty bolts holding the wheel weights onto my M. I am guessing this is because of the old bolts and not the gun, but I wasnt sure if I just needed a bigger gun. (I found an IR 231-A used that I could pick up, and I dont know if I need it)

Thanks in advance, and sorry for the long post.

~Bug

I havent used the gun much, but I have been putting 3-4 drops of pneumatic tool oil in it before each use. I had read in a different post that they also need grease somehow?

I am using the 1/4" quick connects, so maybe I need to make them a size larger.

Ill try the trick on reversing from forward to reverse and see if that helps. For now I am just hitting them with PB Blaster, letting it soak, using the impact on them a little, and hitting them with it again. Im in no rush, so it works for now.

~Bug