While we have never used charge bars for steel shot, I have found that for larger shot (BB and bigger), charge bars are not as consistent as I would like them to be. I have had bridging problems in the drop tube as well.
For large shot, we weigh the desired load of shot and then fill an empty primer tray with them. This will give us a pellet count and then we tape over the rest of the holes in the primer tray.
We then dip the tray into the shot to get the desired load, and funnel it into the wad at the correct stage of the process. It is slower but we do not reload big volumes of steel shot, so it works for us.