This is why I deal with Justin at communitydiscs.com. Any discs that he is unsure of the weight, he personally scale weighs and puts a sticker on the bottom with the scale weight. I have had this issue with various other stores, but never from Justin.
2013 Vibram Disc Golf Street Team
Last ACE: 3/10/2013 - 176g M Ibex
Metal hits since last ACE: 7