Like Dagger said, it takes some force to neck size. And don;t "over-adjust" the die thinking you'll get a nice "grab" on your bullet. If you have to do that, the die is adjusted incorrectly.
There is something about the Lee Collet Neck dies though: Sometimes a guy will put them in the press and raise the ram, with no brass in the shellholder. Pushing up from the bottom, the die can get stuck in the collet forcing cone. Once that happens, you
must unstick it before it will work.
The bottom of the die insert sticks out from the die body a little. Take your thumb and index finger and see if you can spin that insert (or turn it easily, it won;t be so free as to "spin"). If it's hard to turn, chances are the insert is jammed into the collet. Take the die completely apart (all out the top) and unstick it in this case. I use about half a drop of RemOil (don;t ask me how I get 1/2 drop
) and spread it around on the die insert where it goes into the collet. Some guys polish the insert a little to make it smooth. I tried that once or twice, but unless it's overly rough, I wouldn;t recommend that. You could use a tad of white grease too, I suppose. When the die is put back together, the insert protruding from the bottom of the
die body should turn smoothly and have a tiny amount of "slop" in it.
Install it making 100% sure you adjusted it as per Lee's instructions. See, when you install it, you're supposed to raise the ram and screw the die in until it touches the shellholder. This is where the problem starts. There's a little play in the insert, so it's easy to keep screwing in the die, forcing the insert
up into the collet until it stops. If it isn't stuck then, it certainly will be on the first piece of brass that you resize.
So........make sure the insert is loose and turns easily. Then screw the die in until it just "kisses" the shellholder when the ram is at the top of stroke.
In extreme cases, Lee says they'll make an undersized sizing mandrel for you. Some guys have polished theirs using fine sandpaper. But, I reload for 13 calibers, and almost all are rifle with Collet dies. I've yet to have a problem (except when I got first one: I stuck it into the collet!) ((
D)))
Failing all that, I'd call Lee. Something else is wrong.