Rather than check case length and trim only those that need trimming, I have developed a little different procedure. I use the Lee case trimmer, driving the case with a cordless drill and trim each time the case is reloaded. This is just as quick as checking length and separating those needing trimming and has the added benefit that
every case is exactly same length.
To reduce the number of times I must handle each case, I drilled two holes in a short piece of hardwood, then split it through center of holes and mounted the Lee case trimmer and a chamfering tool in the handle.
First all lubed cases are resized, then each case is placed in the shell holder and driven in cordless drill. Step one is to run the case trimmer, then inside/outside chamfering tool. While the freshly trimmed and still lubed case is in chuck, lay down trimming tool(s), pick up a soft cotton rag and hold case tightly while spinning case quickly removing the lube. Once this step is complete, cases are ready proceed w/normal reloading process.
A bit different, but works for me.
Regards,
hm