I seated a bunch of .308 heads yesterday and several seated harder than others. All cases were sized in the same dies, etc. Am I looking at variations in the inside thickness of the necks? If so, how 'bout a suggestion for a reasonable setup (price/quality)? TIA for your help.

I have a wildcat that requires neck reaming and the case form set from RCBS came with a neck reaming die. It's a long die that holds the case like a FL die would and the top of it is long to guide a reamer.

This is really a lot of trouble for such a good standard cartridge like the .308 Win. I suggest that if the groups are not good enough for you now that you buy some new cases. Also a uniform proceedure including the removal of lubricant from the necks may help. There are also carbide expanding balls made by Hornady.

Agree with Savage 99. You can uniform the neck thickness easily with regular neck turning. You don't require a reamer die. They get expensive. A neck turner set to your thinest neck will take care of the inconsistency. Measure the necks of you loaded rounds. That variance can easily tell you your variation.

The easiest thing is to buy a good lot of brass that's consistent to start. In that caliber it's certainly cheap enough and avoids the neck turn which to me is the most onerous task in reloading.