There were some Lee Loader units that reportedly sized Full Length, but I’ve only encountered them in pistol calibers (straight walled). I don’t know for sure if they really FL size, but I recently got a Mequon-era “Unitized” set that is supposed to do it... I’ll post a report when I try it out.

The main rifle calibers for which I would even think of using a Lee Loader are likely to be either bolt action or more likely, single shots. Either way, I would be using the same cases over and over in the same chamber, so only neck sizing should be sufficient to make my reloads work... in fact, having the brass fire formed to the chamber might even be beneficial.

Just my random thoughts on the matter.