Re: 30-06 loads
"Is there any reason i can't try sierra hpbt match kings in 168 grains..."
Understand that NO book data is a "law", including the much confused OAL.
The book makers are only telling you what they used to develop their published data, no more. YOU can use any brass, any bullet, any primer you wish IF you do it intelligently and not by belivening if it's in a book it's safe for you too.
THE cardinal rule is to start with low to mid range charges and ONLY move up IF no over pressure signs appear. If they do, back off. If they don't, it really doesn't matter which bullet you use or how deep you seat it, etc.