22 LR 'rat shot is #12, CCI 22 Mag shot uses #11, CCI 9mm, 40 S&W, 44 Spcl, 45 Colt, 45 ACP all come in #9, some in #4. I have loaded 44, 45, and 38 using #10. The #10 works well on rattlers as do the CCI #9. Sometimes the 22 LR take a second shot to really finish some snakes, but under 6 feet they work. Still, shooting at the head works best. Wife did kill a bunny at 8 ft with A CCI 44 #9. It caught the wads and all, eating a newly planted tomato stalk. Most of them not of much use past 10-12 feet.