spine question

[Snowcrest 6]

Hoping someone can help....

I shot a martin cheetah, 26"DL, 65#, using easton axis nfused 500's and a 125gr montec.  Arrow weighs about 410, I think.

Tech guy at cabelas said I was under-spined and might go to a 400 or 340.


Am I under-spined?  And what's the value of a 340 compared to 300 and 400?

Thanks

 

[cowboystl1]

the guys at my cabelas cant even cut an arrow strait! dont ever listen to those fools man if any thing id think your arrow would be a bit heavy, personally i like them that way better penetration vs the very few fps you might loose. best i can say is set up the targets or go to the range shoot em if you can stack your arrows your fine maybe paper tune a bit if it makes you more comfortable but i think your fine 

 

[Matt Brimmer]

The Cabelas guy was correct This time.  With that draw length, cam style, and broadhead weight you should be shooting a 400 spine. According to the Easton Spine Chart assuming your total arrow length is approx 27 inches the 400 spine would be the correct size.  The 340 would possibly be to stiff causing difficult tunning issues.  The 300 would be even stiffer and even more difficult to tune.

Basically on the AXIS and FMJ shafts the higher the number (600) the weaker the spine.  The lower the number (300) the stiffer the spine.  Not all manufaturers use this numbering system.  They all vary a bit.  Keeping a spine as close to the arrow manufature recommendation typically alows for the easiest tunning.  A properly spined arrow also penetrates better as it is not over oscillating and is able to retain the stored energy of the bow better.

Good luck,
Matt Brimmer