Hey guys. I am going to be using a KOO Defense Carbine Kit on my KWA Glock 17. I have never done a big pistol build before and I have been searching around but there really hasn't been much information for what I require. I don't have a set budget but here are my goals: -Effective range of 200+ feet -Power of 350-370 using GREEN GAS an Propane -Amazing grouping at 200 ft. Thanks for help guys. I will be posting updates and issues regarding this build.