Thier reamer is probably up to SAAMI spec but hornady bearing surfaces are LONG I'll take a look at my 168 eldms but seriously eldm bullets are often seated a bit deeper than you expect because their bearing surface is just so damn long. Like others said don't get to worked up over it it's better to be short than long.
Not to mention, you can't accurately or consistently measure the throat of a chamber based off of a bullet/loaded round.