that would at least give you a rough estimate. if you have a feed mill near by they may have a scale inside you could use or if your friends with some one that works at a salvage yard you could have them weigh it on there scale that they wiegh cans on.
i just ment so it was acurit i shipped something cant remember what it was and my home scale was off on the wieght far enough i ended up not making much off of the sale. shipping companys at least around me are picky.