Had a Bourgault 5350 air tank bridging with summit oats last year. This year I loaded the air tank so the spout was loading to the opposite side as the auger draws from. You could not fill the tank right up, ( but close to full ) and no problem. If you load the cart tank pretty much center, the oats seeds orient themselves to slide down the pile as it forms. They lock together under the weight of the pile and can not crumble and fall into the meter. Kind of like a harvestore silo to try to unload. By loading the oats all to one side, the seeds are all oriented pointing down to the metering auger and crumble apart much easier to keep the meter full. I learned this watching a semi trailer of oats unload. One hopper loaded dead center over the hopper bottom and the other loaded toward the front of the hopper so the pile was sloped toward the start of the hopper bottom opening. Feeding a small transfer auger, the hopper loaded in the center would bridge for the first 20 to 30 bushels until enough of the hopper had unloaded to allow the pile to shift and re-orient it's direction.
It is a bit of a poor explanation, but so far this year, we have been bridge free and seeding oats is stress free.
I understand what your saying Chance2, but in this case, I have had the same problem at times with the JD tank and it is caused by dust in the seed. Some seed lots just have more dust in them. In low humidity it is especially worse as the plastic tank gets a bit of static cling to it, causing the dust to collect on or near the sides of the tank when loading. Then when a clump of dust gets just above the meter, it bridges.
JD 63- Here is the best answers I got....
-Load with your spout STRAIGHT DOWN as to reduce the chance of more lighter material collecting on one side of the tank.
-Agitator on high speed
-If you have a blockage monitor and dual chute, run the starter blend down with the nitrogen instead of with the seed, so if you do have a block, it can instantly detect it.
-And most importantly, although its a pain in the ass, make sure you run you oat seed tank every time before you refill.