Arrow Selection - 3part Question

[Marlin44]

I'm currently using Easton 340 Excel shafts (8.8gpi) and 125gn field points and broadheads out of a Mathews switchy XT set at 70lb. It was suggested to me last week that my arrows are underspined. Im not sure what this means - I'm relatively new to this sport and relied on the shop to set me up accordingly. When I can hold it steady enough I can group 5 arrows into a circle the size of the bottom of a drink can at 30yards, so they seem accurate enough to me ???, although I do get the odd one that enters at an angle - maybe me. Am I using the wrong arrows???

I have been considering changing to some heavier arrows like the whitetails at 10gpi and using same weight b/head combination - is this a detrimental choice??

Would like to have them fitted out with the 2" Blazer vanes??

[aussiehunter]

mate they sound fine to me....

whats ur draw length,

ur shaft lenght,
[measure from end of shaft to groove of nock]

what shafts are u using,brand etc


,ill do a check on easton arrow selection or have a look there.

http://www.eastonarchery.com/downloads.asp

http://www.eastonarchery.com/products.asp?show=chartsSelectors

plus the tuning guide has a wealth of info



if u have ur broadheads grouping well,esp if they group the same as ur field points u r sweet.

those weight shafts will do fine on most game here in aus,except say buff ud want something heavier.

being accurate and placing a sharp broadhead in the vitals is the key

pat :)

[XTfreak]

Have you looked at the Easton Arrow guide? That should answer any question(s) that you may have.
Here is the website.
http://www.eastonarchery.com/products.asp?show=chartsSelectors
Bill

[Marlin44]

I'll measure them up tonight and also put them on a scale to get overall weight.

[Friar Tuck]

Also your draw length would help in assessing the spine.

They sound fine but if you have a long draw they could go a touch under.

[Marlin44]

Draw length - 28.5"

[Kimall]

Mate I have always shot that spine out of my S/Back at that draw length and 70# and it is spot on I would think.Does the advice come from someone that has some experieance or has read a magazine. :? If they are coming out of the bow a bit soft it would be a tuning prob with the rest prob not with the arrows me thinks.
Cheers KIM

[Marlin44]

Arrow length is 742mm (29.68"). Couldn't find my scales to get an accurate weight but the numbers should give me around 261gn for arrow plus 125gn for b'head = 386gn (plus the female insert / ferrule that glues into shaft - don't know weight of these)

Those 2" blazer vanes - how do they perform on hunting arrows.

[aussiehunter]

u need a min of total arrow eight of 350g to keep u in the 5 grains per inch,which u have.

in the easton chart they do recommend the 300,ur on the boarder.

as kimall had said he s uses them fine,the main thing comes down are they flying well and grouping with broadheads.

u can have arrows grouping but be under spine and impacting whilst they are fishtailing,no biggy with target points but im sure u know ud want ur broadheads hitting straight to maximise penertration.

so do u have ur broadhead tipped arrows impacting the same poi as ur field points or at least grouping well.

if u refer to the easton tuning guide i mentioned earlier and go through to broadhead tuning it will explain it all very clearly

if u are using expandables ull find they will mostly shoot like ur field points ,they can hide tuning issues.

personally thats a light setup,suitable for most game as i said before.

i use a 450g setup for deer

if i was travelling to the cape id be looking at a heavier setup

then im up in the 550 plus range,but thats only me personally :)

see how u go

pat :)

[Friar Tuck]

ST Axis setup

Insert weight = 16 grains
2" Blazers = 5 grains each
X Nock = 9 grains

Total arrow weight at that shaft length should go close to 450 grains total

Running the stats as you have them puts them on the weak side.

2 Solutions that come to mind quickly

Go to 100 grain broadheads
Cut the shaft from the back so you get them to 28.5"

Both these options will stiffen then spine up a touch and for added measure you could add a wrap to the back to help stiffen the spine.

I have found it easier to tune the bow to a stiffer spine than to a weak one.

[aussiehunter]

hold ya horses,lets not all panic.. :shock:

first up has he admitted he has a problem yet?,no only that someone suggested he may be underspine...

he is on the border as per recommended shafts..

if his draw length is 28.5,u want at least an inch longer out front for broadheads.so he is right there..

yes he could drop his broadhead weight to a 100g,but as kim as said as well,they shot fine for him.

id wait to see how they are shooting first,just my thoughts :)

[Marlin44]

Yep, broadheads are impacting same as field points (Outback Supremes and Muzzies) They are grouping well and just the odd one enters the target but on a slight angle. Video taped some last week. It may be a dodgy one in the bunch so I'm going to number them and shoot them and see if there is a pattern.

I just ordered some some Vapour Whitetail hunters 11gpi. At same length as I'm using now, overall weight will just over the 500gn mark - should smack them hogs a bit harder.

[Friar Tuck]

I just re-read the first post and thanks Pat :oops:

There doesn't actually appear to be a problem with them.

If they impact the same as your field points and are grouping well then don't try to fix it.

[Marlin44]

Yeh I'm a big believer in the "If it ain't broke don't fix it" rule BUT I'm taking the opportunity to upgrade to heavier weight arrows - it's only money :?

[rory]

By the way......

I have found that no guides to arrow spine is right for my set-up, the constant struggle with arrow flight I was having was due to being underspined massively, even though Easton's guide said not :?

[Marlin44]

I've got shafts organised. Anyone using the quickspin 2.5" fletches. This is what I'm looking at putting on them but I'm concerned about them being able stabilize the arrow.

[aussiehunter]

mate go the blazers,2 inch either 3 fletch or i prefer 4...

talk to willy r...


pat :)

[Marlin44]

Yep - the folks I'm buying the shafts from are willing to set up some with three and some with 4 until we get it right for my bow.

Pat - Sent PM