What Tom said... The barrel should make contact with the bottom of the barrel channel the entire length. You probably won't have a solid black transfer on the wood, but it should be hitting every couple, few inches. I'm thinking that the breech might stand up a little if you tap the muzzle, even with a good fit, but the best method is using some sort of transfer (soot, inletting black, etc) as the best way to check for a good seat.
Also, if you blacken the end of the breach, you should get a good transfer there as well when you tap the muzzle. I'd take a look at that area again if you can get a piece of paper in there, the end of the breech should contact the stock.
Ed