This, exactly.
@inkballedtarget: Don't overthink the whole OAL thing, use whatever works for that barrel/magazine/bullet combo. In my Shadow that means an OAL of 1.09 but my M&P, Glock, SR9 etc. can accept 1.15ish. So why do I load everything to 1.09? Because that's the length that works in all my pistols, regardless of the powder I'm using. Remember to always work up and test any new load and you'll be just fine.