Have any of you experimented with different diameter mandrels? For some folk this is one of the big downfall of the system as opposed to a bushing die in that they can't easily adjust the neck tension - it is what it is, no more or less.
I've seen where people recommended chucking the mandrel in a drill press and sanding it down a thou or so... always seemed like getting a consistent diameter over the length would be problematic. The only area where the mandrel 'sizes' the neck is towards the top end, but if you don't re-size the rest of it as well, wouldn't it affect things when you pull the case back out of the die (over that minutely larger portion of the mandrel)?
I've also heard of people ordering a slightly undersized mandrel from Lee for something like $6 or so (+ S&H)... anybody here tried that?
Lastly... the mandrel doesn't look like the world's most complicated piece of machining - seems like a half-decent machinist or gunsmith should be able to chuck it in a lathe and take a thou or two off the OD easily enough? Or would there be complications when you have to take it out and swap ends to get the whole length again?