6.0 to about 7.5 Red Dot gets you between 800 and about 950fps, barrel length considered. Depends on how you'd define plinking. If you wanted to move up the scale a bit, Power Pistol has worked very well for me in 45 Colt with 260gr cast swc's. 231, AA5, Herco, 4756, Power Pistol, even 2400 in light doses. Again, depends a bit on desired velocity and how hard a cast bullet you're shooting. If pure lead swc's, keep velocity down, or you'll spend more time cleaning your bore than shooting, unless bore's been lapped. You've got lots of options, if you can find the powder.