Countersink rudder trailing edge

Just finished everything but the trailing edge before priming the rudder. I started countersinking and noticed the distinct knife edge when countersinking both sides of the wedge. Is this the norm? I think I'm at he minimum depth possible on the countersink without enlarging the hole... Thanks!

Countersink

Yep. Get as close as you can to a good nesting of the dimple.
Proseal and cleko to a stuff piece of angle then leave it for a week or two before driving rivets.

Ok thanks! I was worried about going too deep so I thought I'd check before continuing.

Knife edge

I should clarify. Get as close as possible to a good nest but be mindful of the knife edge. Try not to knife edge the holes.

Don't overthink this too much. That wedge is going to be glued in, so there will be some filler in those holes. I drilled and clecoed the TE wedges for my -10 to a board (if you don't drill the pilot on the countersink may impact the underlying board). Remember to drill perpendicular to the wedge surface, not the board. The TE of the wedge should be flush with the edge of the board, so the board does not interfere with the countersink cage. Set the countersink to be just slightly deep for a flush rivet (maybe 2 or 3 clicks). Countersink away and then flip the wedge and repeat. The drill holes in the wood will help keep your countersink from wandering.

I preferred to set my TEs wet, as I don't think the clecos provide enough force to get the proseal to ooze out of the joint properly. That's just a personal preference. I have a long length of angle iron (the one used to set the landing gear for my RV-6A), which I clamped to a table edge for support with the angle down. This made a straight back-riveting plate. After riveting, I cleaned the proseal ooze from the manufactured heads and TE and any excess from the shop heads. Some people like to alternate rivet directions but I did not find it necessary and the rivets look more uniform.