Spine Questions

[Crowkilla]

Can someone help me understand the importance of selecting an arrow shaft that is properly "spined" for your bow?I have heard folks talk about being under and over spined, but I have never truly understood what that means.

From what I understand, if yourshaftsare underspined your arrow will flex too much after it leaves the string, resulting in the arrow recovering later in the shot than it would have if itwas stiffer. On the other hand, if you are over spined, the arrow will not flex as it should to maintain a straight path to your target. Is my understanding even close to correct?

Another question, how can you be certain you have selected a shaft that is a proper spine stiffness for your bow? Is the shaft selection grid that is on the back of the box of arrows reliable and accurate? For example, I shoot a BT Guardian set at 70# with a 29" draw. I shoot 350 Carbon Express Maxima Hunters, total arrow weight with broadhead is right around400 grains. These arrows have performed beautifully for me, so I believe they have the right "spine" for my setup.

Anyway, just trying to get a better handle on this. Any guidance is much appreciated.

[6bloodychunks]

with underspined arrows it is next to impossible to get broadheads
to fly with field points.

being overspined is always better than being underspined!!!

arrow length ,point weight ,fletching and nock weight ,
all play a big part in affecting the spine of an arrow.

your setup should be fine ,but for us to know for sure
you would have to give us your arrow length.

takeyour 350's cut to say 28"with 100gn pointsand blazers and cx nocks
then take the same arrow full length 31"+ with 100gn points and same fletches and nock.

the 28" arrow would probably be spined just about perfect,
but the full length arrow may be underspined.

think of it this way....................

(any 1 or combination of ,higher poundage ,longer arrow,
heavier point weight ,lighter vanes and nocks) = a weaker spine


(any 1 or combination of ,lower poundage ,shorter arrow,
lighterpoint weight, heavier nocks and vanes) = a stiffer spine


hope this helps you to better understand the weird world of arrow spine [8D]

[Crowkilla]

Chunks,

That was a very helpfulexplanation. Thanks a lot.

...your setup should be fine ,but for us to know for sure
you would have to give us your arrow length.

To answer your question about my arrow lenght, mine are 28.5" long. Based on your previous estimation, I'd say they're about right.