Ok, got what is supposed to be a 278 gram calibration weight from the local hunter rep. I was at lunch when he came so I did not get to quiz him!!! If anyone else on here has had any luck calibrating one of these machines, please chime in. I have removed the wheel mounting plate and see no where on this machine that would allow me to screw this calibration weight on. Also as I have mentioned before this machine does not have the override position, it has a test position. On the Pre-Calibration check. Exactely what is the cone adapter? And what is the "bell housing". Picture would have been very helpful in the manual. Any help would be greatly appreciated.