I agree with Wncchester, I have 6 or 7 powders in my cabinent, I'll use a slow powder H4831 or IMR7828 for 270/280/243, a medium powder I.E. 4064 or RL15 for 22/250,30/30,307,30/06, IMR4895 for my Garand, W231 for 45ACP. I look for a powder that will produce high velocity with high loading density of 80% if possible, that's not possible for my 45 using W231. The other side of the coin is if I pick up a new caliber it's a good bet I'll have it covered with the powder I have.. William