1776's curly maple block is spectacular!
I've found the hole diameter in the block depends on the ball + patch + lube, so I patch some balls with lube, then try to press fit them ... open the hole up with a small rat tail file or sanding drum. Exact diameter depends on how easy you want the ball/patch to come through.
If .... you are looking for a way to quick reload, I think a lubed/patched/ball grabbed from the bottom of my hunting pouch is best for a follow-up shot. For downed game, I've used a quick re-load with just a bare ball down a fouled barrel, for a close-in shot.
All said, a few patched balls in a maple or wanut block, from your neck on a strap, is a nice addition to a BP hunt.