Spine Indexing - Advantages

[D_Eightch]

As I dive deeper into the world building my own arrows and tuning my own bow I've been looking at spine indexing.

How many of you do spine indexing and what are the main advantages? I'm not a competitive shooter although I have started 3d league and plan on continuing to do so for fun/practice. More looking at getting the most out of my hunting setup as possible.

 

[doverpack12]

Biggest advantage is consistent arrow flight from arrow to arrow. I spine index on a dial indicator device I made but still have to rotate my nocks once in awhile. If you have the opportunity I think the best way is to shoot bareshafts through paper and turn your nocks one by one until every arrow is a perfect bullet hole. This will place the stiff side of the arrow (spine) in the same starting point on every arrow.

I noticed a big gain shooting broadheads. I seldom have the odd arrow that spins true but the broadhead still doesn't impact with the rest of the group.

 

[5MilesBack]

How many of you do spine indexing and what are the main advantages?

I have never "floated arrows" or used a spine tester, however I nock tune every arrow. That's just turning your arrows while nocked on the string and testing until they either all paper tune perfectly.......or they all group tune together.....or both.

The advantages are better consistent accuracy. Every arrow bends or flexes on the shot. If you have one arrow with the stiff side up while nocked, that arrow is going to bend or flex differently than another arrow that is nocked with the stiff side to the side. As with any precision sport, you want as many variables the same for every shot as possible. Think of it like "neck-turning" brass for precision rifle shooters. Just trying to take that variable out of the equation by making them all close to the same.

And for a hunting setup, that becomes even more important because fixed blade BH's will absolutely show any and all variables that aren't consistent. That's why dynamic spine consistency is so critical. Any changes with dynamic spine between arrows will cause a different flex on the shot.......which will show up down range.

 

[Trial153]

i have had indexed shafts and i cant see any difference...maybe it me and i suck.

 

[RCA Dog]

I cut my arrows to length, glue in the insert, add a field point, then shoot bareshafts and turn my nocks until I get the arrows to group properly, as well as fly properly. Then fletch. I don't shoot through paper. I was chasing my tail trying to group bareshafts until I started turning my nocks, because I always seemed to get a couple arrows that either had strange entry angles into the target, or were just way out of the group. I thought it was my form, but in the end, I just needed to turn the nocks.

 

[AZElk]

I have never done any spine testing but I will say I automatically go one spine chart lower when I am choosing arrows. That, for me, has been the one thing that removes my need to nock tune or bare shaft tune. I have shot bare shafts through paper and all of them were a bullet hold without any messing with the nocks.

 

[roadrunner]

I used to, don't anymore. Haven't seen enough of a difference to be concerned.

 

[jlaner0408]

I cut my arrows to length, glue in the insert, add a field point, then shoot bareshafts and turn my nocks until I get the arrows to group properly, as well as fly properly. Then fletch. I don't shoot through paper. I was chasing my tail trying to group bareshafts until I started turning my nocks, because I always seemed to get a couple arrows that either had strange entry angles into the target, or were just way out of the group. I thought it was my form, but in the end, I just needed to turn the nocks.

Do you square your ends before inserting mocks and inserts? I’ve found that helps as well. Wasn’t sure if you did or not

 

[RCA Dog]

Do you square your ends before inserting mocks and inserts? I’ve found that helps as well. Wasn’t sure if you did or not

Yes for sure

 

[Beendare]

I nok tune also....numbering every arrow.

Consistent spine is way more important than a few grains of weight variance. Squaring the ends of your shafts and meticulous arrow assembly really shows when shooting BH's.

 

[Trial153]

i think two very diffent things are being discussed here.

First spine consistentcy. That is each arrow having the same anount of spine measured by is deflection by adding weight to the shaft.

Second. determining the location of the spine( couple of differnt ways to to this, at least in theory). Then marking or indexing that location so each arrow has it as the exzactly the same Orientation during use.


the first is hugely important and is a function of the production and quaility control of the manufacturing of the shafts.

The second is in my option boreline useless. Or at least almost unmeasurable in terms of usfullness.

 

[kicker338]

My 2cents on this, I spine index all my shafts on my string jig, put a little bend in them and rotate, no matter which you bush the bend it always pops up to the stiff side. Tried the float method, too inconsistent. With spine indexing my bear shafts fly straight. Was a little skeptical at first so turned the nocks on some shafts 45dg. you should have seen the ugly tail whip I got from them

 

[5MilesBack]

IMO nock tuning is the easiest way to eliminate flyers. There probably isn't any guarantee that doing this aligns the spine perfectly such as indexing before building them. But it does help to ensure that each arrow is bending the same on each shot, which leads to more consistent accuracy.

 

[RosinBag]

IMO nock tuning is the easiest way to eliminate flyers. There probably isn't any guarantee that doing this aligns the spine perfectly such as indexing before building them. But it does help to ensure that each arrow is bending the same on each shot, which leads to more consistent accuracy.

Not only the easiest, but the last sentence is the reason why. Every arrow is leaving the bow as close to the same way as possible. It wouldn't matter if they were all turned to the weak side or the stiff side of the shaft, as long as they are all leaving the same. It helps cull bad arrows also, as there are some out there and if you are not shooting top quality arrows, it is likely they is one or tow in every dozen. I also only nock tune fletched arrows. My hunting Fletcher's weigh about 20 grains total. Putting 20 grains on the back end is going to affect the dynamic spine of the arrow and it will in turn fly differently than a bare shaft will. You could shoot the bare shafts, but i would use something on the back end that weighs the same as your fletching so are getting the same dynamic reaction out of the arrow as it leaves the bow.

 

[fishstu]

I have my arrows made my Southshore archery who spline test and mark the stiffer spine side. . The cock vane goes on the stiffer spine side which is on the opposite side of the arrow rest. I have found that the spline aligned arrows are mostly parallel sticking into in to the target while the non-spline aligned arrows stick out at different angles more - it is noticeable shooting 20 yard indoor league. As far as accuracy - not sure if it makes a lot of deference for my purposes and level.

 

[D_Eightch]

Not only the easiest, but the last sentence is the reason why. Every arrow is leaving the bow as close to the same way as possible. It wouldn't matter if they were all turned to the weak side or the stiff side of the shaft, as long as they are all leaving the same. It helps cull bad arrows also, as there are some out there and if you are not shooting top quality arrows, it is likely they is one or tow in every dozen. I also only nock tune fletched arrows. My hunting Fletcher's weigh about 20 grains total. Putting 20 grains on the back end is going to affect the dynamic spine of the arrow and it will in turn fly differently than a bare shaft will. You could shoot the bare shafts, but i would use something on the back end that weighs the same as your fletching so are getting the same dynamic reaction out of the arrow as it leaves the bow.

I did all of this monday morning (added 3 wraps to the back of the arrow to get me within 3 grains of my fletched arrows)

Shot my bare shaft and there was a slight tear, so i turned my nock 1/4 turn and hit a perfect bullet hole the next two shots.

Followed that up with turning the nocks on my fletched arrows if there wasn't a perfect hole with them.

Haven't had this much confidence in my bow setup since i've started shooting. I will see how that plays out at 3d league tonight

I do plan on spine indexing my new arrows after indoor league as a starting point and to nerd out a bit more on the build..

Thanks for all the replies!

 

[blkqi]

I have my arrows made my Southshore archery who spline test and mark the stiffer spine side. . The cock vane goes on the stiffer spine side which is on the opposite side of the arrow rest. I have found that the spline aligned arrows are mostly parallel sticking into in to the target while the non-spline aligned arrows stick out at different angles more - it is noticeable shooting 20 yard indoor league. As far as accuracy - not sure if it makes a lot of deference for my purposes and level.

I've been spoiled by South Shore too. His prices are so reasonable that you would need to build a ton of arrows to justify getting your own spine tester.

 

[Btaylor]

Another vote for southshore.

 

[ontarget7]

Depends on the brand and grade of arrows. The most important factor I have found over the years is how they react dynamically. I can take a bunch of different arrows that test extremely well statically but then get deviations when rotating nocks. A more forgiving arrow would be one you have no or very little deviation when rotating nocks with bareshafts.

For this reason I have went with the Red Zone series from Carbon Express

I still index just out of habit but honestly when I rotate to check other positions throughout the circumference of the shaft I get the same results 99% of the time.




Sent from my iPhone using Tapatalk

 

[5MilesBack]

The most important factor I have found over the years is how they react dynamically.

I still index just out of habit but honestly when I rotate to check other positions throughout the circumference of the shaft I get the same results 99% of the time.

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.