I stumbled across a 250 ct box of 40 cal Nosler 150gr HP bullets the other day at the LGS and grabbed them on an impulse. I previously had great fun blowing up H2O filled milk jugs with 135gr Noslers and Longshot powder. My chrony showed quite a few breaking 1500 fps out of my G35 and that was at 8% below book max! amazing stuff. I don't have much Longshot left but I do have a pound each of IMR 800x, Power Pistol, and Ramshot Silhouette. (buying whatever I can find these days) The Power Pistol never broke 1400 fps with the 135 grainers when I compared it to the Longshot. No experience with Silhouette or 800x. The Silhouette is the closest to Longshot on most burn rate charts but I dunno if that equates to high velocity or not. Never heard rave reviews on that powder. I have read about people packing 800x into brass like they are packing black powder down a musket barrel. I'm hoping to get at least 1250 to 1300 fps out of the 150gr Noslers. Which powder would you bust open first for high velocity top end loads?