Spine Indexing - Advantages

[ontarget7]

I look at spine indexing shafts as an initial step that "might" get you closer to consistent dynamic spine reactions, but until you shoot the arrows you really won't know for sure. So I just jump to the LR shooting after building arrows and nock tune until they're all consistent. Starting with 99% consistent arrow shafts would definitely be a plus. I always liked the consistency of the CX Maxima Hunters before they changed them all up. Haven't tried any CX's since.

The dynamic spine reaction consistency around the entire shaft in the Red Zone series arrows is phenomenal.


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[SICARIO]

Static spine testing is a great place to start. I buy my shafts already indexed.

Dynamic spine testing gets you to the next level of consistency. I use the flat line oscillation method on a bare shaft, which is a common practice in the golf industry to locate the dynamic spine.

Once I identify the dynamic spine (generally within 5-10% of the static spine) I fletch them and go test.

Nock tuning really only gets you consistent results through a shooting machine and a ton of iterations.

 

[5MilesBack]

Nock tuning really only gets you consistent results through a shooting machine and a ton of iterations.

Just this week I fletched up some new arrows and shot them from 40 yards. One arrow kept hitting low left, about 3" outside the bullseye and it was the same arrow each time. That only took 3 rounds to be 100% sure it was the arrow. A quick turn of the nocked arrow, and it was consistently hitting with the rest of the arrows. No shooting machine required.

 

[Beendare]

In general, anything you can doo with your arrows to get better consistency and concentricity is a good thing. Its pretty easy to create a lot of excessive work on your setup too.

Just this week I fletched up some new arrows and shot them from 40 yards. One arrow kept hitting low left, about 3" outside the bullseye and it was the same arrow each time. That only took 3 rounds to be 100% sure it was the arrow. A quick turn of the nocked arrow, and it was consistently hitting with the rest of the arrows. No shooting machine required.

^THIS...... exactly what happens to me and my compound. Its a shortcut to Spine indexing.

 

[SICARIO]

In general, anything you can doo with your arrows to get better consistency and concentricity is a good thing. Its pretty easy to create a lot of excessive work on your setup too.




^THIS...... exactly what happens to me and my compound. Its a shortcut to Spine indexing.

I would say for most people nock tuning is “good enough”. Unfortunately I suffer from mechanical engineering syndrome, and have to take things to the extreme.

For most rifle shooters, getting a round that will hit in 2-3” at 100 yards is good enough. Precision reloaders would want that same accuracy at 600yrds.

 

[Brendan]

Actually - shooting a bare shaft and nock tuning is the "Best" way to do it. With a hooter shooter if you've got one to shoot bare shafts at distance. Think about it, all that matters is arrow flight, everything else is a method to get there, it's just not everyone's good enough to shoot bare shafts well and consistently or has a hooter shooter to do it for them, or has the time / space.

Guys like Tim Gillingham will build up a batch of arrows, and shoot every single bare shaft through paper and at a target (I think both?), turning nocks as needed to get the entire batch grouping together before fletching any of them.

Dudley just addressed this on a podcast. He basically says he buys .001" arrows, fletches them, and if an arrow groups outside of his others, he turns the nocks to bring it in. He mentioned on his latest 4 dozen, he hasn't found one he's needed to do that because the tolerances are so good.

Personally, I've played around with FLO but it hasn't made a difference, so now use a RAM spine tester with good bearings on the weight, check ends of the arrow for run-out as I cut them down and install the inserts, then I mark static spine, fletch and go shoot. With buying good arrows, they all shoot better than I do so haven't had one in my last 4 dozen that I've needed to turn a nock on. Not sure if that's marking spine, or more likely just good arrows.

If you really want to go overboard - buy a frequency analyzer. Even a step above FLO testing.

Frequency surveying instruments | GolfMechanix

 

[5MilesBack]

For most rifle shooters, getting a round that will hit in 2-3” at 100 yards is good enough. Precision reloaders would want that same accuracy at 600yrds.

Of course....who wouldn't? A lot of us bowhunters are the same way. We don't want to just hit the animal, we "expect" to hit the hair we're aiming at.

That's why we cut arrows from both ends, square both ends, fletch our own arrows, spin test, and fully tune our setups including our arrows, which includes nock tuning.

 

[SICARIO]

Actually - shooting a bare shaft and nock tuning is the "Best" way to do it. With a hooter shooter if you've got one to shoot bare shafts at distance. Think about it, all that matters is arrow flight, everything else is a method to get there, it's just not everyone's good enough to shoot bare shafts well and consistently or has a hooter shooter to do it for them, or has the time / space.

Guys like Tim Gillingham will build up a batch of arrows, and shoot every single bare shaft through paper and at a target (I think both?), turning nocks as needed to get the entire batch grouping together before fletching any of them.

Dudley just addressed this on a podcast. He basically says he buys .001" arrows, fletches them, and if an arrow groups outside of his others, he turns the nocks to bring it in. He mentioned on his latest 4 dozen, he hasn't found one he's needed to do that because the tolerances are so good.

Personally, I've played around with FLO but it hasn't made a difference, so now use a RAM spine tester with good bearings on the weight, check ends of the arrow for run-out as I cut them down and install the inserts, then I mark static spine, fletch and go shoot. With buying good arrows, they all shoot better than I do so haven't had one in my last 4 dozen that I've needed to turn a nock on. Not sure if that's marking spine, or more likely just good arrows.

If you really want to go overboard - buy a frequency analyzer. Even a step above FLO testing.

Frequency surveying instruments | GolfMechanix

You’re right about bare shaft nock tuning through a shooter. Consistent arrow flight is the ultimate goal. I think bare shaft tuning is a great way to verify and fine tune adjust dynamic spine testing (FLO), and FLO is a great way to verify and test static spine testing.

When I FLO, 4-6 out of a Dozen are spot on to the static spine mark. The others are within 5-10% of the static mark. It’s a slight adjustment but worth the extra step in my opinion.

Static and FLO is only predicting arrow response, so a shooting machine is the ultimate validation.

And yes, I’d love to have a frequency analyzer to add to all of the other equipment my wife thinks is worthless.....