Herman,
The baffle won't really help with that problem.
Certain extruded powders aren't as bad as others.
IMR4198 is a tough one while H4198 goes pretty smoothly. If I want 4831 speed (not in a ML, of course) I go with H4831SC as it flows pretty well, too. So, in some cases you have a choice.
If I'm stuck with a number that meters poorly I will break out the trickler.
The newer electronic scale/trickler combos would be the best fix. You just throw a slightly light charge from your measure onto the scale pan and the trickler will automatically bring it up to your preset chargeweight.