28.25" 2018 with 200 grains worked in my 50 pound super K Bear, when I went to a shorter draw and a six pounds, at my shorter draw, heavier Super K, the same arrows cut down to 27" still shot good and shot completely through the deer I shot with it as well. I think that the 2315 and the 2117s will be too stiff. When you say 200 is that point plus broadhead adapter total? If you go to a fast flight the 2018 may need to have a slightly lighter point something like 175 grains total, which would be for example,a Zwicky Delta with the long aluminum adapter.