You can make a power trimmer out of a standard trimmer by replacing the crank handle with a capscrew with a hex nut. Use a drill to power it. I had to trim .200 off some cases. Only took a few seconds per case when it was under power.
You can work even faster if you use a foot-pedal to operate the case-release lever on the left side. I cut a notch on either side of the lever's handle to allow me to fasten a length of rope to the handle firmly (so it wouldn't slide around). I C-clamp an RCBS case-trimmer near the edge of a table at an oblique angle, and align it so that the rope will hang off the handle at a plumb vertical drop and not touch the table's edge. I drilled two holes at the same end of a piece wood (~1" x 5" x 15") and nailed that piece of wood cross-wise to a scrap piece of 4x4. It resembles a miniature see-saw with two holes where one person would sit, except it's not perfectly balanced; the "hole" end is shorter, and the "unequal" long end rests on the floor because of sheer weight imbalance. Run the free end of the dangling rope through the holes, measure it so that when the pedal is pushed, the lever has enough tension on it to cam open the shellholder, and tie off the rope at that spot.
Put a box of shells behind and left of the shellholder; an empty box behind the "lathe", and get to it--LF on the pedal opens the shellholder, LH feeds a new case, RH operates the drill, LF opens the shellholder, RH removes the sized case, LH feeds a new case, RH operates the drill, etc. 400 shells an hour in my sleep. My best time is 700 shells/hour, but
that was work; and a timed test just for curiosity's performance.
Also, a 1/4" universal socket joint between the drill and the crank handle shaft will allow "slop" so the drill's alignment isn't so critical. Even better is to build a platform for the drill so it doesn't move much (a simple cardboard box for a platform will do, just so you can align the height of the drill even with the shaft).
Hmm. somebody asked for a description of this a long time ago.. it might get buried here. Pardon me if I start a new thread describing this.
+3 on the Imperial Die Wax.
Thank you, Uncle Don and Matt-man!!