Inherent slop. in fact the Lee progressives do have enough leeway that it takes an awful lot of adjusting to get them to work right. I have had about every kind of progressive and the Lee for some odd reason are not consistently perfect. Esp priming...which in a progressive metallic press can be the dangerous part. Even RCBS has made a few items not well thought out. I've run the Star's and CH Marks and they worked pretty well . Another Lee quirk is the o rings on the dies...easily replaced but they tend to not stay adjusted as they should esp on a progressive. Too much going on. The reason people like the Dillon's and even the Hornady progs is they usually can be depended on to work consistently with very little adjustment needed. For those who use the Lee's and like them most are very detail oriented(and some OCD). I sold and worked on Mec Dillon P-W and Hornady/Pacific presses. But never Lee. Most of the problems they had were user generated... Lee does make some neat innovative stuff...but because of price points use too much plastic which DOES wear and degrade over a shorter period of time than most others.If you can get a Lee Loadmaster to work consistently day after day week after week. Congratulations. Life is too short for most of us. I have a Lee Classic Cast Turret. Also have T-7s. BTW the average Lee user did buy the Lee because of the price of their stuff. Not because it was as good...but was just good enough for them. And that IS the truth. We all have our cheap ideas...a few actually work