corn meal is a common BUFFER. What you're trying to do is make the load complete the cylinder length. Not so much so, that the projectile sticks over the end of the cylinder, because then the cap and ball revolver will not rotate properly.

So in my case, I load; 25 grains of 3f JSG powder - felt wad (instead of the corn meal buffer) - .451 round ball - then enclose the end of the cylinder with a solid type lube. This prevents a chain fire from occurring. So some, instead of a wad, use corn meal, cream of wheat, oats, and what his does is helps prevent the chain fire, also it fills the cylinder. Some claim the grains also help to keep the barrel cleaner. I use JSG so I do not worry about that.