I too love the 40's. Same recipe as JB55 posted. I believe that the extra rotation from a 1/8 twist adds to the efects of the bullet. I wonder if there is a way to measure the RPM's/FPS in different twists to see how it effects the Bullet ?
I have shot many Coyotes with the 40's with mixed results, 100 yds and farther, no exits and no splashes. But 40's when a Coyote is closer, all bets are off. They are indeed accurate little bullets. Interesting thread.