I can't find any proofmarks anywhere on the barrel or the gun for that matter. I have attached a link to gmail pictures of the gun they aren't the best but best I could get it to do in this light. I'll try and get some more light if these don't help.

http://picasaweb.google.com/jshayes99/Charlin02?authkey=Gv1sRgCNK_lYrBoNGrcQ&feat=directlink