Chad,
As colodog noted, there is quite a bit if difference in OAL in most bullets (
MY OCD calls +- .003 "quite a bit") and you must accurately measure from that part of the bullet where the shank begins, requiring a bullet comparator such as the Hornady in conjunction with an overall length gauge such as this one;
LINK,
and using a specially modified case for your caliber of choice, such as this one;
LINK .
As to a micrometer seating die, the only ones I have used are Forster's Benchrest Seaters and they work really well for me.
LINK Ed
