Question on arrow weight, length, and spine

[DeanoZ]

I just purchased a new bow and am looking at potentially new arrows.  In exploring all the new options out there (and there are a few) I've been looking at the Easton N-Fuse and the Gold Tip Pro Hunters.  I already have the Beaman ICS Hunters and have no issues with them...provided they still fit my setup I was planning to use them.  My question though is in understanding Arrow Weight, Size and Spine.  I'm shooting 70 lbs, have a 27" draw length, and use a QAD Drop Rest, so according to what I've been reading my arrow would be anywhere from an an inch or two less than my drawlength (depending upon where the rest is positioned on the riser)?  Then in looking at the sizing charts, with a 26" arrow it appears my arrow size would be a 400?  Now does that size equate to weight in grains or just the size of the arrow?  According to another source I was reading your arrow weight should be no less than 5 grains for ever pound you pull...so at 70lbs that means the minimum weight should be 350 grains correct?  So a 400 would be heavier or lighter than a 340?  I know this sounds simple and I'm probably over thinking this but if you look at the mfg sizing charts they almost make it sound as if a 340 is heavier than a 400?  Spine I get...a .001 is stiffer/straighter than a .003 or .006...I think your literally splitting hairs in the distinction but I get it nonetheless.  Would appreciate someone walking the dog with me on this subject so I can select the right arrow. Its darn confusing!

[DeanoZ]

Anybody?  Was this topic already covered?

[paulie]

As far as arrow length, I would say it's a matter of preference (to a point). I have a 29 " draw and I shoot 29 " arrows (with a QAD rest), my arrows stick past my rest by an inch or so. Now, as for 400's vs 340's vs 250's, I believe that # represents the spine. Arrows of the same spine can vary in weight (grains per inch) from one brand to the next. For example, Beman 400's are 9.1 gpi as to where Carbon Express "Maxima Hunter" 250's (which is what their chart calls for your set up to use), are 8 gpi. But the Carbon Express "Piledriver" (250's) weigh 9.7 gpi. Your arrow lentgh and draw weight will determine the spine as for weight (grains per inch which determines total weight) you have the option of going light, heavy or somewhere in between. Hope this all makes sense and, I hope it helps!

[DeanoZ]

it does, thanks Paulie

[paulie]

Glad I could help!!

[Lot to Learn]

I went through a lot of this trying to figure out what I was going to use this year, this is for gold tip pro hunter, http://www.goldtip.com/prohunter.htm,  quite a difference between 340 and 400 on this arrow.   I ended up with gold tip xt hunters. 

[hookset6969]

If your shooting a 26'' arrow at 70# you will need a 400. Even though this may seem like a softer spine arrow your arrow length is stiffening your spine. For instance I shoot a 25'' arrow and I'm spined perfect shooting 500's. I have a hard time getting an arrow to spine out thats weight exceed's 345-350gr

[DeanoZ]

ORIGINAL: hookset6969

If your shooting a 26'' arrow at 70# you will need a 400. Even though this may seem like a softer spine arrow your arrow length is stiffening your spine. For instance I shoot a 25'' arrow and I'm spined perfect shooting 500's. I have a hard time getting an arrow to spine out thats weight exceed's 345-350gr

Yeap exactly what I went with...but now I seem to be having a problem with paper tuning as I'm knock left and a little low...makes me wonder if I'm still under spined, even though all the specs say a 400 is what I should be shooting

[Randy3003]

The number you are referring to (340-400 ect.) is in fact your spine stiffness.  If you are shooting a draw weight of 63 lbs. or more, you should be shooting a spine of 340 down to even 300.  A spine stiffness of greater then 350 (numerically) are for lower draw weights (55-63).  The carbon express arrows are different however.  Their numbers are actually reversed (smaller numbers for smaller draw weights and larger for larger ) but the draw weight cut offs are relatively the same.  In picking out the proper arrows for you depends upon what you intend to do with them.  If you intend on hunting with them as most of my clients do then and would like to prolong the life of you bow then my suggestion to you is to stay away from the real light weight arrows.  Also keep in mind that the weight of your arrows transfer directly to Kinetic Energy, which is the force that relates to penetration after contact.  I personally give up a little bow speed for a little extra weight as It seriously adds to penetration.  If you are hunting deer I would recommend an arrow weight of approximately 10 grains per inch or heavier per inch.  The 5 grain per pound is the weight at which the IBO rating is set and is very light, in many of my fellow hunter's eyes to light to be considered a good hunting arrow.  Arrow length is also important as it translates to total arrow weight, but should fit you and your bow.  I am a guide here in IL and recommend to my clients here to use an arrow as heavy as they are comfortable with but try to not go less than 10 grains per inch and to try arrows 1 inch longer than their draw length. The spine weights/per pound of draw weights are approximates but through my dealings with various arrow manufacturers this is consistent with them and their spec.  Good luck and If I can be of further assistance IM me  R. Kirby  CEO Kirby custom arrows