"Correct" arrow length

jonUK76

Member
What is the shortest that you would suggest cutting arrows?

On my recurve setup, I'm currently using A/C/C arrows which have been cut to 28.5" AMO, with 100 gr points. The points are fairly long and add at least 1/2" to the arrow length, possibly a bit more. I have my clicker set to very approximately half way up the screw in clicker extension on my riser (a W&W AXT if relevant).

The Easton catalog states about measuring the arrow to 1" (minimum) forward of the arrow rest at full draw to get the "correct arrow length". It doesn't specifically state whether you should allow for the point length in this calculation.

This has all come about because I'm starting to shoot at the longest target ranges (100 yds, 90m) for the first time, and at 90m I've found I'm at about the limit on where I can move my sight and still hit the target. I've been shooting and grouping well at 70m for a while. I have had a suggestion about getting lighter arrows (ACE's or X10's) cut significantly shorter (perhaps as short as 27") which I estimate would take the cut arrow, less pile, to be almost level with the pressure button at full draw (perhaps just an extra .25" forward of the rest), basically the idea being to shed as much weight and excess length as possible from the arrow. The ACE or X10 points add a fair amount of length to the arrow once installed, so even this short the chance of me overdrawing off the rest is (I think) going to be minimal. But is this a good idea?

Thanks
 


LionOfNarnia

Supporter
Supporter
What length/weight limbs?

To me, it would seem strange to shorten your draw to increase accurate range - or your arrows for that matter if you're already shooting fine at 70. I can absolutely guarantee that getting A/C/Es or X-10s will substantially reduce your account balance though ;)

I'll be hitting this same issue in the not-too-distant, my sights are pretty max'd at 70 M.
 


geoffretired

Supporter
Supporter
The first thing I would do is to check where the point of your arrow appears against the target to reach the 90m.
For example, imagine you aimed with the point of the arrow in the gold. Where do they land? If they land low, you would need to raise the point and aim above the gold.
When that happens you cannot use a sight because the gold is obscured by the arrow.
If you have to lower the arrow point to hit golds, you are in with a chance.
Often we can bring the sight right back to the riser to get a clearance between sight and arrow path, and still reach the gold.
In some cases( I know because I used to do this) you can push the sight right out and set it below the arrow with a bit of clearance. In most cases the scale bar will need to be lower on the extension bar so the sight can be lowered far enough to reach under the arrow.
When you draw the bow, and settle at full draw you will see the sight sticking out beyond the arrow point. It will appear higher than the arrow point, so when the sight is on the gold the arrow will be below the gold and not obscuring your view.
If you go for lighter arrows, I would try to keep them a bit longer than your suggested minimum to allow a bit of room for your draw length to increase, just in case you find you are under drawing at present.
 


jonUK76

Member
What length/weight limbs?

To me, it would seem strange to shorten your draw to increase accurate range - or your arrows for that matter if you're already shooting fine at 70. I can absolutely guarantee that getting A/C/Es or X-10s will substantially reduce your account balance though ;)

I'll be hitting this same issue in the not-too-distant, my sights are pretty max'd at 70 M.
Hi Lion, the suggestion is not to shorten the draw at all, but basically to shorten the arrow to the absolute minimum it can be while still accommodating the same draw. I.e. instead of having the clicker well forward on the extension bar like it is now, having it strike somewhere on the riser. I'm (now) using Uukha 68" EX1 Evo2's @ 42 lb (need to check weight at the fingers) and my draw is circa 28". It's kind of a long story but I started off the day shooting my 36 lb Winex's which I have been using for a few years, fully wound in, which results in 39-40 lbs at the fingers at my draw length. With these, I couldn't get a sight mark at 90, so I switched to the Uukha's which I've had in reserve for some time (ebay buy..). With the limb bolts wound out 4 turns, I was able to shoot them comfortably and they allowed me to hit the 90 consistently with the sight bar pulled in and a safe amount of clearance for the arrow.

Thanks for your suggestion Geoff. I'll have to check that. I never look at the arrow point while shooting (I am beyond hopeless at barebow too...) so I can't say with certainty, but I am somewhat sure that the arrow point is below the target at 90m. On reflection it must be as the sight, fully pulled back, is as good as level with the arrow tip at full draw, and the sight is a safe distance above the arrow for clearance. I did notice the clicker and maybe the point obscuring my view when I dropped the sight really close to the arrow, while attempting to get a mark with the original limbs I was using.
 


geoffretired

Supporter
Supporter
I never look at the arrow point while shooting
Heehee, no, I don't suppose many of us do, we are too busy looking at the gold, or the sight ring/dot. But when we do it will always appear below the sight, and when we use the arrow point to aim it will land higher than with the sight. So if the arrow point on the gold won't reach the gold, we have no chance with a sight.
It can be quite therapeutic aiming with the arrow point. Knowing the clicker is dropping can be a real benefit. and you don't need to quickly look to the gold; you already are! heehee
 


Corax67

Well-known member
On my recurve setup I too shoot ACC’s measuring 28.5” nock throat to point of tip (100gn) with a clicker set fairly close to the same point as yours on my Inno CXT.

With my sight, a Shibuya Dual click, I have at least 2.5” left to go on my sight bar at 100yds - I am currently shooting 42# Hoyt G3’s but still had an inch or so left with my W&W 36# limbs.

If you have decent grouping at 70m then the arrows are well spined as they stand and shortening them will make them stiffer which in turn will affect your grouping - this will be far more pronounced as you’ve gone up in distance.


What poundage limbs are you using ?



Karl
 


Rik

Supporter
Supporter
Last time I looked the notes on the Easton chart specified the "correct" length as not including the point (there's a fairly clear diagram) and says that to measure it you mark an over length shaft 1 inch in front of the arrow rest at full draw.
That means that some points will protude past the riser, of course...

But that's "correct" in the sense of "this is what the charts expect". Deviating from that means you're deviating from the charts, but it depends on whether that bothers you...
 


jonUK76

Member
On my recurve setup I too shoot ACC’s measuring 28.5” nock throat to point of tip (100gn) with a clicker set fairly close to the same point as yours on my Inno CXT.

With my sight, a Shibuya Dual click, I have at least 2.5” left to go on my sight bar at 100yds - I am currently shooting 42# Hoyt G3’s but still had an inch or so left with my W&W 36# limbs.

If you have decent grouping at 70m then the arrows are well spined as they stand and shortening them will make them stiffer which in turn will affect your grouping - this will be far more pronounced as you’ve gone up in distance.


What poundage limbs are you using ?



Karl
Thanks Karl, that's interesting. I suppose seeing as we seem to be using similar setups to some degree, one reason I'm running out of sight travel and you aren't might be down to differences in anchor position relative to the eyes etc. I think I'm right in assuming things like face shape can make quite a difference? BTW I wasn't considering cutting the existing arrows but more likely getting ACE's correctly spined for the shorter length. ACE's are a fair bit lighter than ACC's anyway though, so I'm thinking it might not be necessary to cut them so aggressively, which as Geoff pointed out gives little room for error.
 


KidCurry

Well-known member
I don't know where I read it but somewhere I recall that the point needed to be at least an inch beyond the button to get the correct arrow node alignment and oscillation, but don't quote me on this 'till I find it again.
Out of interest what size fletchings do you use? These can have a big impact on down range cast.
 


jonUK76

Member
I don't know where I read it but somewhere I recall that the point needed to be at least an inch beyond the button to get the correct arrow node alignment and oscillation, but don't quote me on this 'till I find it again.
Out of interest what size fletchings do you use? These can have a big impact on down range cast.
Do let me know if that info comes to light again :) The fletchings I'm using now are XS Wings 50mm low profile spinnies.
 


bimble

Well-known member
Supporter
Fonz Awardee
Ironman
I don't know where I read it but somewhere I recall that the point needed to be at least an inch beyond the button to get the correct arrow node alignment and oscillation, but don't quote me on this 'till I find it again.
Well, there's the catalogue for starters... ;) remember that the very front of the shaft can't flex because of the point pile.

The Easton catalog states about measuring the arrow to 1" (minimum) forward of the arrow rest at full draw to get the "correct arrow length". It doesn't specifically state whether you should allow for the point length in this calculation.
 


Corax67

Well-known member
Thanks Karl, that's interesting. I suppose seeing as we seem to be using similar setups to some degree, one reason I'm running out of sight travel and you aren't might be down to differences in anchor position relative to the eyes etc. I think I'm right in assuming things like face shape can make quite a difference? BTW I wasn't considering cutting the existing arrows but more likely getting ACE's correctly spined for the shorter length. ACE's are a fair bit lighter than ACC's anyway though, so I'm thinking it might not be necessary to cut them so aggressively, which as Geoff pointed out gives little room for error.

I anchor below my jaw - never given any thought to that affecting sight positioning.

Didnt realise it was the new arrows you were proposing to have shorter :) as for fletchings, my own fletching are 1.5” Bohning shield vanes which are very low profile.





Karl
 


jonUK76

Member
I would think that those with (for want of a better term) a "longer" face, having more distance between their jaw and eye, would get more elevation at a given sight position (and hence be less likely to run into problems with sight marks) than those with a shorter face. It makes sense in my mind at least :boggled:

On the times I shoot barebow, I often forget to change anchor from under the jaw to the corner of the mouth for the first shot or two, and when this happens my arrow usually fly's well over the target... Small changes make a big difference to where the arrows go..
 


4d4m

Member
I would think that those with (for want of a better term) a "longer" face, having more distance between their jaw and eye, would get more elevation at a given sight position (and hence be less likely to run into problems with sight marks) than those with a shorter face. It makes sense in my mind at least :boggled:

On the times I shoot barebow, I often forget to change anchor from under the jaw to the corner of the mouth for the first shot or two, and when this happens my arrow usually fly's well over the target... Small changes make a big difference to where the arrows go..
Yes, simple geometry will tell you by how much. Just multiply the change in vertical change anchor point by the ratio of the target distance to the "sight base", ie the distance from eye to aim point (sight pin, arrow point, mark on bow)

For example if your eye is 1m from your sight pin, or arrow tip, or whatever is serving as a "foresight", then the difference in point of impact is just the anchor point change times target distance in metres. So a 1cm lower anchor would mean arrows going 30cm higher at 30m.

Using 1m just makes the numbers easier, it would be ridiculously long for arrows e.g. if using the point as an aiming mark, but quite plausible with a recurve sight on an extended sight bar. In reality it might be more like 80cm from eye to aiming point, in which case multiply by the ratio of target distance to sight base.

So vertical change in arrow impact point = vertical change in anchor point, multiplied by range to target, divided by sight base
 


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