2 Arrow choices which one to go with?

[Husker]

From the 3R calculator I've got these two choices.
GT 3555 30.5" arrow length with 100gr field tip 3x4" feathers (354gr total weight)
GT 5575 31.0" arrow length with 145gr field tip and 3x4" feathers (427.5gr total weight)

My bow dynamic computed to 62.4 and the 3555@62.4 and 5575@63.6
Bow is martin sabre 40lb@28". draw length 27.5". I guessed the string as fastflight 10 strand, insert 11.4grain and nock at 10

I'm leaning towards the heavier arrow. These are intended as target arrows. I have GT 400spine spiral flu flu which seem to fly pretty good. They measure 31" from nock crotch to end of arrow, 100gr tip with total weight of 438 grain.

Just looking for some confirmation from the experienced brains here.

[SwampRabbit]

I am not experienced... but I would go with the 427 grain for two reasons.

1) You are closer to the 10gpp "rule of thumb" for a hunting setup.
2) With a 145 gr head, if you find out you are underspined, you can drop to 125 grain head to compensate.

Just my 2 thoughts.

[RickBarbee]

For some reason, that 3R's calculator is way off for you. Don't know why.

Your bow only calculates to just under 55# dynamic energy.
To use the 5575's you are going to have to front load them a lot, and they are going to be real heavy with extremely high FOC

The 3555's are you best option, and you are going to need 145gr points.

You didn't say whether you are getting GT Hunter Black, or GT Trads, so here is a calculation for each.

These calculation have the length adjust to show the closest match, BUT you will want to start with the shafts full length, and take them down 1/4" at a time until you achieve a good tune.

Hope this helps.

Rick

[RickBarbee]

Here's you a calculation with 5575 GT Trads for a comparison.

Rick

[Husker]

Thanks Rick, I was using the Martin Jaguar assuming it would be close to the saber. I couldn't find anywhere what to use for center cut on the generic....-.1875 was giving me close to the same results as the Jaguar..which auto fills a -.75 for center cut. The other various recurve take downs were calculating in the 62 # range as well? The sabre has a compound bow riser so is that what might be making the generic calcs you show so different from the other take down recurves? (I was using the GT black hunter as well)

I think I'm going to just have to find time to get to X10 when they have time to help me tune...never realized the science of arrow selection was so much more indepth than what I went through on my compound .

[RickBarbee]

Husker, I just used generic, but I guarantee it's real close.

The important thing is to get all the entries correct. If you notice, I entered -3/32 for the strike plate position. The reason for this is the Sabre is cut 1/2" past center, so if you adjust the arrow to exactly center you have -3/32"

Just remember whatever you do - always start with the shafts full length & work down 1/4" from there. These calculators at best will get you dead on, but often will only get you into the shaft you need, so never trust the length as gospel.

Rick

[Husker]

Rick, I measured from center of arrow perpendicular to riser to be exactly 3/4". Am I confusing center cut? Just trying to educate myself on all the terminology.

[RickBarbee]

Looks like you have the rest & arrow adjusted pretty far outside of center, but hard to tell in the picture.

The inside of the riser wall at the hole is where you should measure from, and from what I read on the Sabre, it is 1/2" cut past center.

In this picture the red line indicates the riser wall where the measurement should be taken, and the green line indicates where the rest & inside of the arrow shaft would be if the arrow were setting at true center.

Keep in mind, I'm just guessing from what I can see of your picture, but the description should be correct.

The farther away from (outside of center) you go, the weaker the spine of the shaft will have to be.

Rick

[RickBarbee]

I strongly suggest you find someone that has a center shot alignment tool, and use it to find true center of the bow. Then you can work from there.

For me, I've always found that my tunes are better, and I shoot more accurate with the arrow just a tiny bit outside of true center. Even when shooting off an elevated rest.

Rick

[Husker]

2 Arrow choices which one to go with?

Yea I'm going to go and get some assistance getting it tuned.. Save myself headache and probably $ in the long run.
When I sight down the string with string parallel to riser the tip of arrow is in line with string so I feel I have it centered.
Thanks for all the feedback.

[Bisch]

Rick, can you post a pic of a center shot alignment tool?

Bisch

[Tracker0721]

I was using the elevated rest on my new jag elite but am now trying to build the plate out, didn't reach 3/4" but those things are way past center. Got a bare shaft, leatherman, felt tape and tape measure and a couple days of headaches saying I'm not perfect yet. But boy is a tuned arrow worth it.

[RickBarbee]

Rick, can you post a pic of a center shot alignment tool?

Bisch

Bisch, this is the style that most trad bows would probably use, and easy to use.



Risers that are flat & square on the outside & have sight bushings (like the Sabre) can use one of the fancy laser light tools.

Rick

[Ntexasarcher]

Both