I've had problems with gouging like that before on a Lee mold. I found it was due to a burr on the edge of the sprue plate. I fixed it with about 30 seconds of light filing on the plate. The gouge is still there on the mold but it doesn't seem to hurt anything.
When I get home I'll be taking the sprue plate off to check for this very thing ... and prolly giving it a light sanding no matter what heh.
The gouge I've got crosses with the base of the bullet, and there is some visual concerns... but the dropped lead says it don't matter.... so... I'm not too concerned.
I've also noted on this particular mold, the sprue plate gets tighter with use rather than loser. So while casting this afternoon I started loosening the sprue plate screw by a quarter turn every dozen breaks or so.
