I have both the Collet dies and Redding precision necking dies with bushings. I like the simplicity of the Lee collet dies. How far did you turn the necks down? It should not make any difference how thick the necks are, the collet should squeeze the neck down to the spindle, making the inside the same no matter the out side diameter. If you have turned the necks down a good bit, there may not be enough material left to "set" the neck inner diameter, springing back after sizing. The nice thing about the bushing type dies - if you do not have enough bullet grip, you can just plop another bushing with a smaller diameter in. Since I load mostly for 224 calibers, I have bushings from .241 through .250 and I find the size that gives just enough bullet tension with out distorting the neck when the bullet is seated. In general I have found the Lee collet dies do not give a bunch of bullet tension, but enough to get the job done. I have one for 22 Hornet, that does not give enough bullet tension. I can pull the bullet out with my fingers and if I am not careful, I will push a bullet right into the case. I solved that one by using my 221 Fireball neck sizing die with a proper bushing to give me just the right bullet tension. Even though I have a Redding precision neck sizing die for 223, I still use the Lee collet die. I seems to control the run out in the necks and it does not distort a whole lot when seating a bullet. Good Luck and Good Shooting.