VihtaVuori N565 High Energy Smokeless Rifle Powder 1 Lb By VihtaVuori ITEM DESCRIPTION now offers VihtaVuori N565 High Energy Smokeless Rifle Powder 1Lb. This N565 was created especially for the .338 Lapua Magnum with 250 grain ammunition. Specifications & Features: Temperature stable Improved hygroscopic stability New decoppering agent to ensure a cleaner barrel when shooting Flows smoothly through powder measures Single perforated extruded powder