Timely topic! Just today I got some of those JSB KO 10.03gr slugs and wow do they ever look like what the FX Halo was supposed to look like. Anyways, I know a lot of you guys are going to crap all over me for mentioning it, in a post about a really good gun, but, I shot these out of my Hatsan Vectis today. They took about 30 shots to settle down and lead in, and then they shot almost as good as the NSA 12.5gr. I shot a rather nice sub 1/2" group at 40y and then went out checking Strelok data to real targets. My speed was 965fps and they sound good hitting things. Certainly nothing left to ricochet with these things. I can't wait to connect on a starling, my NSA's were ice-picking them w/o expansion but these are not going to have that problem. What I meant by almost as accurate as the NSA is that in zero wind they might actually be as good, but with any wind they won't be. You can most certainly notice the difference in drift going from a bc of .075 to .047. I was just getting use to the .075 but I want to see these Knock Outs earn their name even more, still a better bc than any pellet.