Mine was JUST like JC's, and my solution was to simply pop out the carbide ring. It will now work equally well on my 45 ACP, 45 Colt, and 454 rounds depending on how, and in what press I set it up in.
There again, I purchased it on sale simply, like a lot of others, to see what all the hub bub was about. IT DID work fine with jacketed with no issues what so ever, as most of them are under the actual diameter I need to use lead with. But there again EXACTLY like JC, when I ran a lead bullet up through it they all came out sized down below what I need to avoid leading.
Pop out the ring, and problem solved for all future use. My standard die sets have no problem producing fully functional ammo for all calibers I load for, the FCD as simply something to check out, mainly to see if I could get a bit more consistency with a couple of powders I was playing with at the time I decided to pick it up.
I also use quite a few Lee products and can say in all honesty they work well for the money spent on them. I would not try and replace them with something else simply due to the price being higher and hoping for better performance. This said they have and do continue to have a few issues with tolerances, fit, and finish, in some of their lines. Does this mean I am going to ship my FCD back to them, nope much easier to pop out the offending ring. Now if it were a bullet mold, or set of dies out of whack, yep it would be on the way back ASAP, as I have done in the past.
Mike / TX