Hi Matt
Welcome to the forum--come often and stay late.
Also, welcome to the society of deranged single shot shooters (handiholics for short).
I'm a bit uncertain about your post. When you state that the rifling appears a bit shallow towards the tip, do you mean towards the muzzle?
A rifle bore that is larger inside at the muzzle end than it is at the chamber end is definately a recipe for poor accuracy. The only way to determine this that I can think of at the moment would be to slug the bore. for instance using the fishing sinker method; push a slug of soft lead through the barrel from the chamber end and feel if it gets noticeably easier towards the muzzle. You could also start a slug at the muzzle(gotta be careful that you don't damage the crown) and then push it out after an inch or so, and do another one at the chamber end, and then measure the two to see what if any difference you come up with.
You should also check the crown by first cleaning it up real good with solvent and a patch, just wipe all the fouling off until you can see the blued metal, then dry it with another patch or rag. Then, take a q-tip or cotton ball and using your finger trace the edge of the hole in the muzzle. You're feeling for tiny burrs or snags. Also look to see if any cotton material has stuck to the metal in this area. There should be no snagging or roughness here. Then, shoot the rifle a few times, 10 should do it; then inspect the crown visually. You should find a star-shaped "shadow" of fouling deposited on the surface of the muzzle. This fouling pattern should be evenly deposited and centered on the hole. If not, this indicates a problem with the crown.
You should also read the stickies at the top of this forum, about the FAQ and accuracy and all.
The easiest thing to do, would be to take Tom's advice and send it back to the factory if it does turn out to be the gun and not the shooter. If you check out the crown first, and find a problem there, this knowlege will give you a starting point when you talk to customer service; if you do wind up sending it to the factory any info you can give them about what may be wrong with it will help.
Good luck!