I don't think the difference is anything to worry about, but there are a couple of things you can do to limit what variation you get. First off, as has been stated, measure to the ogive of the bullet rather than the tip. There could easily be .009" variation in the actual bullet length from the same box. If you were getting .0005" variation in OAL, perhaps you should be giving us advice!!
Keep your dies clean. A slight build up of mung on the contact surface of your seating stem could cause inconsistant results.
When you seat your bullet, don't slam the press handle to the end of it's travel. Gently push the bullet in about half way, then turn the case a quarter turn and push it in the rest of the way, then turn the case another quarter turn and ensure that it is pushed all the way home.
A compressed powder charge could cause the bullet to push back slightly resulting in some OAL variation.
A rubber O ring under the lock ring of the seater stem will allow the seater stem to find it's own center. I got rid of the retaining spring that holds the shell holder in place and use an O ring for that also, allowing the shell holder to slide freely in the ram slot for the same reason.
Lube your case necks with dry graphite, particularly if you resize with an expander ball. Inconsistent neck diameter due to poor expander ball use will cause variation in bullet seating depth. For easiest results resize the neck with a bushing die and resolve the problems that can be associated with an expander ball.
