Bourgault 7700 metering accuracy trouble.

We are running a new 7700 bourgault tank. It seems that my fertilizer especially is running out earlier than it should. Up to 25 acres on a full tank. I put in proper density and recalibrate. When I enter full tank it shows I should get x amount of acres. But I am not it is usually 10% out at least. I have been having trouble with fert accumulating on my one stainless metering auger. That is causing some issues. When I was using a sulfur blend it seemed to have built up big time. Now I have moved away from sulfur and I am guessing that the crud is breaking off. Because recalibrate every tank and have been having about 7% calibration fluctuation between every Cart full. Not that I'm happy about that but I can understand what's going on in that metering auger. I should be removing it and cleaning it I know. I do not have the scale option so I can not weigh my product accurately unless I take it to town which I will prob be doing soon. I just wondered does anyone else have this issue with a 7000 series or know what could be causing it. Bourgaults way of calibrating seems bullet proof. I enter my density and it should know how many pounds are in that particular tank. And yes I am dividing my weight of Pail by 1.04 to allow for proper square foot measurement. Also Tare my scale for pale weight. Canola and innoculant worked out perfect for me. All other products seem to be going down heavy.

Bourgault 7700 metering accuracy trouble.