A true magnum spherical rifle powder, it's superb with heavy bullets in major, overbore rifle cartridges. US 869 It appears like there is a node at 43g and at 43.9g with IMR 4166 in my situation. 43.9g starts to indicate some tension in the LC brass and Savage chamber https://imr4064smokelesspowder8lb53074.blog-a-story.com/19855666/goex-reenactor-black-powder-1-lb-for-dummies