I wanted to be able to precisely control the neck tension in my tight-necked 30-06, so some sort of neck sizing die seemed to be in order.
I've never had good luck with Lee products (other than their ladle-pour pot) but had heard good things about Lee collet dies.
I had been warned to grease the collet, so I did. Nonetheless,the die simply would not work as it came from the factory. It took a hammer to budge the collet inside the die, and no matter how hard I sized the cases, the neck ID never changed (0.308" - 0.310" on fired cases with turned necks).
After pounding the collet out of the die with a punch and hammer, I found that the inside of the die had been machined with a chainsaw. Or so it appeared. It was terribly rough.
So I honed the bore of the die. I didn't try to get a perfect finish, just knocked down the worst of the chainsaw marks until it was possible to move the collet around inside the die with firm thumb pressure.
I also polished the mating surfaces of the collet assembly.
However, it still would not size my turned necks -- the necks were still coming out with 0.308" - 0.310" ID.
Maybe the 0.305" mandrel is too big, when springback is factored in?
So then I tried sizing an un-turned neck. When sized as deeply as possible, it came out 0.307" -- and I had to really lean on the reloading press to even get that much sizing.
Then I tried sizing my turned necks without the mandrel. It worked! By carefully adjusting the sizing depth, I was able to sneak up on 0.305" - 0.306" ID.
So I guess the collet die will do what I need it to do, though I'm less than thrilled with Lee's quality. Lee has a lot of good ideas that they proceed to ruin with cost cutting measures.
I may replace the lame o-ring die nut with a "real" lock nut since die adjustment is critical when sizing without the mandrel, and it would be nice to have repeatable die settings. Alternatively, I could machine a smaller diameter mandrel, but since sizing without the mandrel works OK, what would be the point ?