I just looked at reloading data on the Nosler Load-data site for some of the most popular calibers, and have to ask; Why H1000? The most universal powders across numerous calibers, even .338, are IMR4895 and IMR4064. However , for the larger calibers, .338 and up, IMR4350 seems to be one of the better. I see no reason to be hung up on one single powder when there may even be a better performance powder available. It's ludicrous, go to this site load-data.nosler.com and select the caliber and bullet size and you will see numerous powders listed, including the most accurate tested. Don't get hung up on one powder!