Arrow spine for Hex 6.6

Johnh159

Member
Hi all
A subject that's been covered a number of times but I'm still getting confusing results.
Set up:
25" Riser
Long Hex 6.6 making 70" bow
Draw 31"
Limbs 36#
On the fingers 43#
+4mm Tiller
7.25" brace height
Center shot just about 0 - a smidge outside

Shooting both X7 2214 & ACE 430
ACE - 110 grn points, shooting with Easton pin nocks and XS Wings

Per the Easton Charts Group T9 430-470R ACE & 2214 X7

Both spines are coming off stiff (I know the ACE's are one spine stiff according to the chart but thought that should be about right for the Hex 6.6). Bare shaft in black of 122cm face at 30m. Also bare shaft impact nock to the left.
Winding up the limbs makes little difference.

Walk back test (from 70m back to 18m) with fletched arrows just about bang on.

As the arrows (ACE's) seem to be flying ok, I'm inclined to put it down to my dodgy release and ignore the bare shafts.

Thoughts?
 

Timid Toad

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I'd look for bh 8"+. I'm shooting a 68" bow on 7.5" bh. My guess is your arrows are *appearing* stiff as the back end contacts either the riser or the rest. Raising the bh will also affect the arrow position wrt centreshot, so move it out a little more. I'm still using the right hand edge of the arrow on the left hand edge of the string (I'm right handed).
You don't say how much your limbs are wound in, but that can affect things too. But for now, give the above suggestions a try.
TT
 

Johnh159

Member
I'd look for bh 8"+. I'm shooting a 68" bow on 7.5" bh. My guess is your arrows are *appearing* stiff as the back end contacts either the riser or the rest. Raising the bh will also affect the arrow position wrt centreshot, so move it out a little more. I'm still using the right hand edge of the arrow on the left hand edge of the string (I'm right handed).
You don't say how much your limbs are wound in, but that can affect things too. But for now, give the above suggestions a try.
TT
Thanks.
Sid recommended 7 to 7.5 brace height

Sent from my D5803 using Tapatalk
 

Timid Toad

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Sid sn? Naughty! Ilfs do seem to like a higher bh than a bolt down. More to do with the button, in my view.
 

Timid Toad

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You'll know when the bh is right. It'll sound and feel completely different.
 
25" Riser
Long Hex 6.6 making 70" bow
Draw 31"
Limbs 36#
On the fingers 43#
Have you measured the force on the fingers with 43lbs?
For me it sounds strange - because I have also 31" drawlength and ordered my long limbs HEX 6 BB2 to get 44lbs on the fingers.
So Border made that, and wrote onto the buttom limb: 41lbs at 28" on 25" riser...
And that's correct, I measured it on my drawboard.
So, I'm expecting that with 36#limbs you will get to 39# at 31". And therefore the spine will be too stiff of course.
 

Timid Toad

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Have you measured the force on the fingers with 43lbs?
For me it sounds strange - because I have also 31" drawlength and ordered my long limbs HEX 6 BB2 to get 44lbs on the fingers.
So Border made that, and wrote onto the buttom limb: 41lbs at 28" on 25" riser...
And that's correct, I measured it on my drawboard.
Depends on the riser, and how wound in/out they are.
 

Johnh159

Member
The limbs are 36# at 28".
Pulling 3" over that so 43# isn't beyond the realms of possibility - as TT says, depends on how wound in/out they are.
 

Timid Toad

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Ah, Hex don't work at 2lbs/inch. You'd better get them weighed properly. 6s are about 1.4lbs/inch iirc.
 

Johnh159

Member
1.4# x 3" = 4.2#
Adjustment on the riser +/-5% (so max of 10% adjustment altogether).
Again not beyond the realms of possibility that 36# limbs at 31" makes 40.2# with the bolts out, wind half way in, (+5%) gives another 2#????
 

Johnh159

Member
Anyway, whether pulling 41#or 44# and whether its 30.75" draw or 31.25" draw still puts it fairly into the t9 Group on the Easton Arrow chart - so will try TT suggested solution of increasing the bh to approx. 8" and see how we get on.
 

Mark31121

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I second the BH increase, I had mine (long 6.5's on a 25" ILF riser) a bit low and couldn't get the tuning to work well, after playing with the brace it changed everything completely and the sound is fantastic - sounds like a "thwwwm".

For the bareshaft to be that far out it does sounds like a contact issue as even a couple of spine groups out mine ended end up within a foot (so bareshatfd red/blue at 30m on a full 122 target).
 

Johnh159

Member
I shot last night, indoors so only 20 yards, but raising the brace height brought the bare shafts back where they should be.
With the lower bh (7.25") the bare shafts were low and left (in the 5 ring on 60cm target) - raising the bh to approx 8" brought them into the gold.
The issue now is a noisy bow. Tried bh between 7.5" to 8.75" and settled for 7 7/8 but still louder than I would like. Also pushed the center shot out a little.
Will try to get outside on Saturday and will work on it again.

Wondering if the ACEs are a little light. Total arrow weight 337 grns + XS wings.. According to the Border resource page, they are borderline (no pun intended) @43# they recommend minimum weight of 316 grns + 10% (297 grns at 41#).

Thoughts?
 

Timid Toad

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I don't shoot ACEs off my Borders: very noisy. You could try a string with a couple more strands.
 
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