I had to shim the charge bar on my 410ga MEC 600jr.
It leaked powder really bad using the factory charge bar.
Just used some business card cardboard to do the job.
The bar itself was loose enough to be rattled up and down while it sits in the chrome plated steel channel it rides in on the machine.
I took a piece of cardboard the width of the channel an slipped it underneath the bar on the powder (left) side of the bar. It extends all the way to the drop tube in the center but doesn't interfere with it.
At the left end I just folded it around and down and taped it into position to hold it there.
You may have to experiment with the length of the shim as well as the thickness to get the right working combination.
The cardboard shim boosts the charge bar upwards a tiny bit and holds it against the rubber washer with enough pressure to seal it so the powder doesn't leak out.
With out it, there was enough room between the bar and the top of the channel for powder to migrate through there and spill out as you operated the bar back and forth. Made a real mess.
Shim has been there for about 6 years now. Still going strong.
It's on the bottom of the bar, so it doesn't interfere with removing or filling the powder bottle. Nothing was needed on the lead shot side as the shot is big enough not to get through any space between the bar and channel. There doesn't seem to be a problem on that side anyway, but if there was, I'd shim that side too.
Don't seat the powder bottle too tight. Just firm enough to seal it down.
The combination of the brass washer and the rubber one with a tiny bit of pressure from the bottle will seal it just fine.
w/o the brass washer used in combination with the rubber one, it may still leak some powder, especially with flake type powders.
