Re: Neck sizing BH .308 with Lee Collet Die
Don't sweat the outside measurement, unless you're concerned with clearance in a tight neck chamber. The inside neck diameter is what's important. I swear by LCDs and all of my LCDs give .002 to .003 neck tension. If you desire more or less tension, Lee will make you a custom mandrel for 5 bucks.
Since you are new to the LCD, I suggest you search this site as well as others to properly set up the die. If it is not properly set up, you can (will) apply too much force to the die and push the mandrel out the top of the die, stripping the aluminum top nut in the process.