The FIRST thing I do when planing for any build for myself, especially a Wildcat is to buy at least 100 pieces of brass. If it is going to be a match rifle, I size them up or down as the case may be, then turn the necks on 10 to 15 to find out what it takes get a 100% clean up. Then load some bullets into 3 or 4 of them and then add .003 to that measurement and then order reamer. If it going to be a hunting rifle and I can use Lapua brass, I bypass the neck turning and maybe add .004, depending on whether it is a repeater or single shot.
This has worked for me, I am sure others have their methods.
Never base your reamer neck diameter on what worked for some one else, you do not what brass he used whether he allowed .003 or .008 clearance etc.
Dave