RE: Ontarget2 Run
I left it at 4 feathers and it comes out to an "optimal" spine of .3067. That is also with "hunting" selected which will give you a little stiffer spine in the optimal range than "target". FOC is 12.73
You can probably use them with no problem. I made the shaft a .5" longer (30.5) and it brought the spine down to .3017