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? Wanna kill these ads? We can help!