Are there any guidelines or can you offer any advice on accpetable neck wall thickness for a
wildcat. I have been miking cases and reading various forums and there are a variety of neck
wall thicknesses. The range seems to be from .010 to .015 inches. I am experimenting with necking down a case and I get about .015 inch neck walls. If this is not too thick then I won't have to thin the necks which I consider a pain in the arse.

First thing is who reamer are you using, one a gunsmith has or are you ordering one? If it's one the gunsmith has it will have neck size on it, if you order one you can do whatever neck dia you want.
I don't mind turning necks give you an example. I just had a 6x250 build ordered the reamer with a .270 neck which I need to just clean up the necks to .0125. The average thickness of the brass I have is between .013 and .01425. I could of ordered a .274 neck and not bother with necks but being a varmit rifle I wanted to get the best out of it. All my reloading is done with bushing type dies. Well good luck.

One of the reasons I prefere designing wildcats with long necks with thin walls is it seals easier if case to chamber clearances are equal. The use of lower pressure reduced loads comes into play as well as the use of cast bullets. Moving a wall thickness of .015" as compared to .011" to acquire a seal is significantly greater. That is of course if clearances are the same. Also seating lead bullets into thick necks can be combersome if you use the same expander as you do with jacketed bullets. For myself I opt for the thinner necks; easier to anneal and less cracked necks generally, clearance beeing a factor. roger

There is also the issue of caliber and neck tension. The larger the caliber, the larger the neck wall thickness of course. Although, not proportionally! Perhaps the 6PPC would be a good example of what is optimal in the 6mm bore. Generally the neck thickness is about 8 1/2 thousands. As we know the benchrest crowd centers around what works.