I have a Lyman 49 that I'm pulling data from and under the .308 section the diagram at the beginning shows an OAL of 2.810. The OAL under the .308 load data for the 168 gr. HPBT shows an OAL of 2.775. Assuming I'm not playing around with bullet setting depths, which I'm not, which one do I use?

I am loading up 168 Amax, with Varget, and will be using the min. of 41 and a max. of 45.7+ Sierra HPBT 168 data information. I will stop at 44 gr. or sooner if I find something she likes. Do you seasoned hand-loaders rely on the load data from the powder manufacturers or the data from the bullet manufacturers? I want to purchase the manuals that make the most sense for hand loading not just purchasing manuals for the sake of having manuals.

If I'm missing something using the Sierra 168 HPBT/Varget data for the 168 Amax, please let me know.