I don't mind having one size per operation
I'm going to look into it. Flat bottom too is a nice touch
You can buy end mills cheap on ebay. I use em in my tailstock quite often. I use the 1/2 inch end mill for boring a plug hole in a join or shaft. 1/4 for 5/16 pins, and 5/16 for 3/8 10 pins. Just make sure your tailstock is in line with the headstock, because these suckers cut regardless of where they are at, lol. I moved my tailstock and didnt get it centered back berfect, and when i bored a hole for a pin, it was supposed to be .312 but it ended up being .326! Lesson learned, lol.
Joe