I myself do not trust Sierra data and definately not the techs. Dave brown and Paul Box seem ok. None of it is taken with a pressure barrel, and every issue they have, loads vary greatly. I even see where a heavier bullet has same max loads for a lighter one. And I will never talk to that Duane Serics, or treece. Guys, they are people, not the end all be all of reloading. There is dozens of articles out there in precision rifle, handloader and other, that discuss this. We have all read them.