I have 2
 

I have one of the motorized RCBS trimmers and it does just fine. Also have a 3 way cutter for it and it really is neat. For my 223 brass i have a Gracey and it does trim them all the same...at least the ones shot in my rifle. Both do down to about what Catfish said. Bout .0005...according to the dig. :D BTW those digital devices are soo much better for me. Same with the motorized thingies. Just lazy.

Skeet, you are right. I mis-read - I thought I saw .0005 also.

Realoading Bench - Trimming
 

I am not sure what the problem is that you would accept 0.005 tolerance in your case length after trimming. I have been using a Forster trimmer for years and would never accept that much variation. That is a personal preference, not a commercial. Now I would purchase the Redding 2400 model because it has to produce a square mouth and the accuracy should be +- 0.001.
Then neck size so your cases don't grow on each firing.