Age and spine
Moon, I was 10 when I shot my 1st deer with a bow. I loved Robin Hood and shot thru-out my childhood years. I love long bows and recurves but now want to really long range hunt. Where I live in NE AR, there are no CFs allowed and only 7 total spreadout days of ML/shootgun hunting but there are 5 months of bow/x-bow hunting in this agricultural environment. I hunt no where else. My Parker Saf Mag was highly adequate to 80 yds. I am hoping for 120 with the SF. I am a 6PPC benchrest shooter and am deep into precision shooting with both 3 6PPC rifles(1 bench and 2 varmint) and my 22-250AK IMP. When the same principles are applied to the x-bow, or even compound(which I shoot my Hoyt Razortec to 100 yds) , surprising results can occur. Adequate ranging, great optics, extreme attention to matched bolts, adequate fletching stabilization for the point used, etc all contribute to perdictable long range shooting. I expect you both are well beyond me in this regard. Spine: we are aware of arrow tuning for vertical bows. I believe the length of the arrow necessitates tuning and the fact that the arrow will flex upon shooting. I think it would be desirable to have NO flex what-so-ever. With the x-bow, I think such is the case. I don't think they flex, or at least should. The steering of the point must be controlled by the fletching and the FOC gives a degree of stability. Apparently, more FOC is needed with bolts than arrows. I have wondered if straight fletching might be better with traditional broadheads to help reduce their steering and slight offset would be better with expandibles and fieldpoints, but this is just speculation.
I appreciate you guys being willing to share your expertice.