I use a dial caliper I ordered from Midway. Accurate to .001 and a lifetime guarantee. Actually it is marked in .001 increments, but you could estimate a little bit closer by position of the pointer in between the marks. They do have an electronic caliper that is good to .0005, but to get down to .0001 I think you would have to go to a micrometer. I am pretty new to the reloading game, so I keep everything pretty mild, and am not to concerned about measuring things down to a ten thousandth of an inch. I also only use brass from ammo fired in my own guns, so far I am am still on once-fired brass. Maybe as I get more experience, and acquire more toys I will do it, but that seems more in the territory of the hardcore match shooter.
[This message has been edited by bergie (edited May 08, 2000).]