arrow spine - too stiff....

[darthTer]

Doing some tuning for the outdoor season on Friday night, appeared to show my arrows up as being still (always felt that they were...).

Shooting @ 30m, the bare shaft initially hit the wooden frame of the boss, gold high to the left. After a bit of tinkering, I managed to get the bare shaft hitting the foam, still gold high, but not even on the 80cm face. All fletched shafts on or around the gold. Arrow flight also appeared bad, with the nock end kicking way out to the right.

If I was to drop down a spine, would it be enough to get the bareshaft either in, or pretty close to the fletched group??? or based on the distance, would I be more looking at dropping 2 spines???

Bow spec:
Samick Masters with 36# Border HEX 6 H bb2, giving a 70" bow.
Draw approx 30.5" giving approx 42# OTF
Arrows - Easton ACG 430, 120gr points (I believe)

Easton shaft selector is suggesting a 480 spine for recurve....

Cheers

 

[blakey]

If I was to drop down a spine, would it be enough to get the bareshaft either in, or pretty close to the fletched group??? or based on the distance, would I be more looking at dropping 2 spines???

Bow spec:
Samick Masters with 36# Border HEX 6 H bb2, giving a 70" bow.
Draw approx 30.5" giving approx 42# OTF
Arrows - Easton ACG 430, 120gr points (I believe)

Easton shaft selector is suggesting a 480 spine for recurve....

Cheers

Generally speaking at our club we reckon that the Easton charts are always too stiff. I usually go 2 spines under their recommend. As you're using 120 points you'd have a way back if you end up too weak. But I do understand from the lads who shoot Border, that Hexs shoot very different to the Easton charts. Perhaps it might be worth contacting Sid before you spend? Is there anybody in your club who could lend you some arrows to try? Cheers

 

[Tuck]

I get to a T8 spine which is 540 spine ACG .... 2013 chart


Eat, Drink, Shoot, Enjoy.

 

[Timid Toad]

Hi Darth
I'm shooting 500 spined X10s off my Hex6 BB2 mediums, off an Inno Max. 28 5/8" (29 5/8") overall length 120gn points, 43lbs otf. I can also shoot 450s, slightly longer, but the 500s group better at distance. It did take a bit of experimentation to get the arrow over centre right.
TT

 

[Tuck]

Darth have you measured the otf poundage, and correctly measured the arrows and your draw length as Easton chart defines, and noted the 'R' for recurve notation? These are all reasons that people find that the charts are 'too stiff'.
Heavy points can affect the spine weakening by about 1/2 - 1 spine. I recently made a set of ACEs tunable by going from 80 to 120 grain piles. Limb efficiency will also affect this, Hex 6 store more energy for a given draw length, see Sids posts on this subject in the BB threads.
Be careful when changing point weights as heavier points are longer.


Eat, Drink, Shoot, Enjoy.

 

[darthTer]

I have historically shot 500 spined arrows - latest being SkyArt SF Ultimates. When I moved from the HEX 5's to the 6's (same weight), the Skyarts made the bow sound very noisy - i put this down to under-spined shafts hence the change to the 430 ACG's which are heavier & stiffer. Using these the bow sounds nicer but the flight is not too great.

I know I can pick up some 480 spined shafts for a good price, so it may be worth a punt to see how they go.

 

[darthTer]

I am looking @ a 30.5" shaft. However the Easton shaft selector doesn't give 1/2 lengths.

for a 31" shaft, it recommends the 480 shaft, but for a 30" shaft it recommends the 540 shaft. I am inclined to go for the stiffer of the 2 options....

 

[Tuck]

I am looking @ a 30.5" shaft. However the Easton shaft selector doesn't give 1/2 lengths.

for a 31" shaft, it recommends the 480 shaft, but for a 30" shaft it recommends the 540 shaft. I am inclined to go for the stiffer of the 2 options....

For Hex limbs and a heavy point weight I would agree, BUT best to confirm OTF and what length adjustment options you have for future arrow tuning.


Eat, Drink, Shoot, Enjoy.

 

[darthTer]

For Hex limbs and a heavy point weight I would agree, BUT best to confirm OTF and what length adjustment options you have for future arrow tuning.


Eat, Drink, Shoot, Enjoy.

OTF is 42/43#
Required shaft length - 30.5

I have been shooting long enough to know that the above is correct!!!

My main concern was around whether changing by one spine will be enough to bring the bare shaft into the group. I know the HEX series of limbs don't always play nicely with the Easton chart - been shooting them for years.

 

[Tuck]

OTF is 42/43#
Required shaft length - 30.5

I have been shooting long enough to know that the above is correct!!!

My main concern was around whether changing by one spine will be enough to bring the bare shaft into the group. I know the HEX series of limbs don't always play nicely with the Easton chart - been shooting them for years.

You'd be surprised how many experienced archers misread the charts or measure DL wrong affecting draw weight too.

As the ACG are available individually you could get a couple of the stiffer spine ones and try them out as they seem likely to be the best bet.



Eat, Drink, Shoot, Enjoy.

 

[Timid Toad]

My experience of the Hex series is that I have always returned to the same spine there or thereabouts. The different speeds are accommodated with setting the arrow's over centre. My Hex6s run so close in that I can just see the barrel outside the string and the edge of the point. This seems to stiffen the behaviour nicely.
If flight is a bit iffy, do a contact check if you haven't already, I've found a stiff arrow of a Hex6 BB2 is more likely to strike the rest and flick out the back end. This makes it appear even stiffer, because of the absorbed energy. The low BH and speed of the arrow passing means sometimes it hasn't completed a flex cycle and passes the riser tail end in.
Another thing to try is moving button and rest into the furthest hole. It cheats a bit more of the flex cycle. I've got a twitchy bow hand but I'm not finding any problems shooting the bow like this. The other option is to reduce point weight. It might sound counterintuitive, but the lighter point will cause the arrow to flex less on loose.
I don't want to teach my Grandmother to suck eggs, just running through some of the possibilities that I've found worth a try before shelling out on new kit.

 

[darthTer]

My experience of the Hex series is that I have always returned to the same spine there or thereabouts. The different speeds are accommodated with setting the arrow's over centre. My Hex6s run so close in that I can just see the barrel outside the string and the edge of the point. This seems to stiffen the behaviour nicely.
If flight is a bit iffy, do a contact check if you haven't already, I've found a stiff arrow of a Hex6 BB2 is more likely to strike the rest and flick out the back end. This makes it appear even stiffer, because of the absorbed energy. The low BH and speed of the arrow passing means sometimes it hasn't completed a flex cycle and passes the riser tail end in.
Another thing to try is moving button and rest into the furthest hole. It cheats a bit more of the flex cycle. I've got a twitchy bow hand but I'm not finding any problems shooting the bow like this. The other option is to reduce point weight. It might sound counterintuitive, but the lighter point will cause the arrow to flex less on loose.
I don't want to teach my Grandmother to suck eggs, just running through some of the possibilities that I've found worth a try before shelling out on new kit.

So...Do you find that a slightly weak arrow performs better??? or is easier to tune???

 

[Timid Toad]

That's been my personal experience, but it is still stiffer than recommended by Easton.

 

[darthTer]

That's been my personal experience, but it is still stiffer than recommended by Easton.

based on that then....Easton recommend a 540 spine for a 30" shaft, and a 480 for a 31" shaft. If I opt for the 480, that brings me into the slightly stiffer range.

Alternatively, I see one retailer selling Nav FMJ's with a 510 spine.

 

[Tuck]

Watch out for FMJ weight.



Eat, Drink, Shoot, Enjoy.

 

[darthTer]

Watch out for FMJ weight.

According to one source, the weight is about the same as ACG's @ 8.4gr/inch - which I was quite surprised at!!!

 

[Timid Toad]

Ha, Tuck, these are Hex6! I shoot Nav FMJ for clout, with 140gn points and I still have a sightmark for 140yds!