Spine questions

Hope this isn't a stupid question but I have never learnt much about spine of the arrow? I am shooting a mathews mission craze at 25" draw and 65# draw weight, I shoot 100grain heads. I was told to use 500 spine arrows so that's what I use (easton powerflights). Is that correct or should I be using a different spine, also what difference does it make and that does the spine number actually mean. Thanks

 

Arrow Spine Chart by Deflection, Carbon Arrows All Brands - Hunter's Friend

Looks pretty close but probably a bit under.

 

So close enough, I might be raising my poundage a little bit soon?

 

What's the arrow length? That's the more important measurement. Just off a guess of what the arrow might be I would say you need a 400 spine. And yes there is a big difference between 500 and 400 especially when talking about broad head flight.

 

And spine means stiffness of the arrow. As an arrow is shot it will actually bend 3 or 4 times back and forth until it settles in. Using correct spine ensures your arrow stabilizes correctly for your set variables. Draw weight, arrow length, tip weight. This is especially important for broad head flight.

 

if your raising your draw weight soon I would go to a 400 spine...with your short draw length I assume the length of your arrows is short also...so you should be plenty good with a 400 spine arrow and a 100 grain head

 

Defitely need to go 400 if you raise poundage.

 

Arrows are cut at 27" thanks for all the help

 

Yeah your well into needing a 400 spine. I would just go ahead and do that right now.

 

Which ever arrow brand you use you can always check on line one the company's arrow spine chart. It'll show you different arrow lengths and the spine they recommend. I shoot under my recommended spine and works for me has been for years.

 

I shoot a Easton fmj 400 at 28" from a 72# bow

 

A couple things...

1. Always know your spine and it's never a dumb question
2. Why is your arrow so long? 27" arrow on a 25" dl... just kind of long. Reducing your arrow length will help stiffen your spine.
3. I would go to a .400. If your arrow is over spined, it will react much better than if it's under spined. Shoot a fixed blade on an arrow that's slightly under, vs. one that is slightly over... huge difference.

Also, if you ever want to add weight, you can add weight at the tip and improve the FOC of the arrow. This improves flight and penetration.