Nock tuning results

[sickles107]

I have always nock tuned. Don't want to get into a debate weather it's repeatable or not, I have rolls and rolls of wax paper with sharpie and little holes showing that nock position certainly effects a paper tear.

My process has always been

1. rough tune the bow with a bare shaft

2. nock tune a batch of 4 bare shafts, find a common tear for each arrow/nock position, set them to that.

3. Fine tune the bow to those arrows to shoot a clean tear

4. Find the commen nock setting for the rest of the arrows to shoot a clean tear

5. fletch everything and go shoot


On rip tkos, I always used the spine align mark for reference, and always laughed when there was no consistency going off that. A batch of arrows that all teared clean would have the spine align mark in all different positions. And there was always 3 or 4 arrows in a batch that didn't quite tear like the others, but we're close enough. I would shoot every arrow in four positions to find the right nock setting.

Today I decided rather than reference off the spine align mark, I would reference off the seam in the carbon. Something pretty obvious I overlooked, and BAM consistent tears for each nock position. Anothing interesting find is the arrows that didn't quite tear like the others were the arrows that didn't have a straight seam, but a curved seam.

Results below, going to tune the bow to seam down (D) position as it produced the least variance in each arrow, and in the middle of each tear result.

biggest thing is now I will set all the rest of the arrows to that setting to start, and hopefully not have to shoot them all through paper in all 4 nock positions!

 

[Billy Goat]

Fyi, I found after fletching, the nock position would change from where it was with bareshaft.


That's when I'd nock tune bareshafts, fletch, then put through a shooting machine and finding I'd need to tune again to group tune a batch of arrows.


Tim G has said same thing and why his process is just to tune for consistent tear after fletching.


I haven't tested as much with paper, I just have always tuned for impact point, but did find difference pre and post fletch. And I'd use electrical tape on the shafts to match weight of fletching.

 

[Bump79]

I'd be interested to know if it correlated to a spine tester. Or a first bend.

 

[sickles107]

Yup, will run fletched shafts though paper after as well, didnt include that above. I just like to nock tune before fletching to get all the shafts the same. Usually don't see much inconsistencies between fletched shafts once they are nock tuned bare, but will have to tune the bow slightly again.

 

[Jon_G]

Thanks for posting your results. Getting some new arrows this week and I will be nock tuning as well

 

[N2TRKYS]

How do your broadheads fly at your normal hunting ranges?

 

[Billy Goat]

I'd be interested to know if it correlated to a spine tester. Or a first bend.

Doesn't correlate to spine tester, that I found. Only messed with a few dozen.

That's what I use to do. I never floated shafts, or did any of the things to press a shaft and see where it bent much.


I found with group tuning, the stiffer the shaft, the less tuning it took. One of the additional reasons I don't worry about supposedly "too stiff"

 

[Billy Goat]

How do your broadheads fly at your normal hunting ranges?

3x to 4x tighter after nock tuning in several instances.

Starting with straighter shafts helps tho.

 

[N2TRKYS]

3x to 4x tighter after nock tuning in several instances.

Starting with straighter shafts helps tho.

For context, what size were your groups before nock tuning?

 

[Billy Goat]

For context, what size were your groups before nock tuning?

Not uncommon to see 6- 8" @ 40 yards with large fixed blade heads. That's with .005+ shafts, without nock tuning. And that's with a machine that will put the same arrow back in the same hole.

And understand a lot of times you aren't getting .005 shafts when that's what you buy. Few days ago I took some .005 shafts, put them on dial indicator and found the straightest 28" sections. 9/12 I got to .002. One no matter what was .015.

Nock tune those arrows so group hits same hole, or say fall within 3/4 and that broadhead group will shrink way down. It will still magnify anything that is off, but groups will be down to under 2" usually.

Start with straight shafts, and group tune, you can virtually put every shaft back in same hole as it made with a field point. Assuming a quality broadhead, mostly meaning one that spin straights. And especially square shafts when using .204 or smaller shafts and hits or outserts. Even after squaring, if using an outsert you still need to index the halfout so it spins true, and then hope the damn thing don't bend.


Bows are different, not all will shoot the same. Some are very consistent. I expect my 3d and field arrows to tune to same hole, or wear out the same hole (I use cardboard so it sometimes walks a shaft into the hole).

 

[Billy Goat]

I don't usually nock tune my hunting arrows anymore. I buy straight shafts, square them, spin check broadheads.


I'll shoot them and if I notice one or 2 don't seem to fly with the group, I'll rotate a nock.
Won't notice that with FP's, but shooting broadheads you can.



Limiting factor isn't if the arrows will shoot a 1.5-2" group at 40, or 1/2". It's if I (or any other hunter) can make the shot every time.

 

[N2TRKYS]

Not uncommon to see 6- 8" @ 40 yards with large fixed blade heads. That's with .005+ shafts, without nock tuning. And that's with a machine that will put the same arrow back in the same hole.

And understand a lot of times you aren't getting .005 shafts when that's what you buy. Few days ago I took some .005 shafts, put them on dial indicator and found the straightest 28" sections. 9/12 I got to .002. One no matter what was .015.

Nock tune those arrows so group hits same hole, or say fall within 3/4 and that broadhead group will shrink way down. It will still magnify anything that is off, but groups will be down to under 2" usually.

Start with straight shafts, and group tune, you can virtually put every shaft back in same hole as it made with a field point. Assuming a quality broadhead, mostly meaning one that spin straights. And especially square shafts when using .204 or smaller shafts and hits or outserts. Even after squaring, if using an outsert you still need to index the halfout so it spins true, and then hope the damn thing don't bend.


Bows are different, not all will shoot the same. Some are very consistent. I expect my 3d and field arrows to tune to same hole, or wear out the same hole (I use cardboard so it sometimes walks a shaft into the hole).

I don’t think I’ve ever experienced groups that big at 40 yards. However, I don’t think my broadhheads are what’s considered large.

I’ve read here a good bit about nock tuning, but don’t remember folks ever mentioning how big the group sizes were before or after.

I don’t guess the GoldTip Hunter XTs that I use are considered straight, compared to some other high end models. I only cut mine from one end and have just about quit worrying about squaring up the ends after cutting.

Thanks for the info. Very interesting.

 

[mod-it]

I had the same experience as Billy Goat on my last set of arrows I put together. They were GT Velocities, .003" I think.
I normally nock tune by group tuning arrows but used paper this time. It was winter and cold outside is the only reason, lol.
I cut from both ends, squared all ends, glued in inserts, and installed nocks. I have never worried about clocking arrows but actually did with this set, I checked two arrows and they spun left out of the bow. Then I shot them all as bareshafts (I tuned the bow to the first couple so I could try to get bulletholes) through paper at 8' and turned nocks until all were shooting the best bullethole I could get. I had one in the group that I couldn't get to make a bullethole, it's best position still had about a 1" nock left tear.
I marked them all and then fletched, a 3 fletch with 2.1" Q2i x-ii's with 2.5° of left offset.
After they were fletched, I shot them all through paper again at 5'. None of them were shooting bulletholes but about 6 of them were making the same tear as each other (not a real bad tear but not a bullethole either). The other 5 (I left one a bareshaft for a tuning arrow) were making different random tears.
I tuned the bow to get the 6 making the same tear to give a bullethole, and then turned nocks on the rest of the arrows to try to get them to make a bullethole. I ended up being able to get all but one of them to do so. The one that wouldn't was the same problem arrow that wouldn't give a bullethole as a bareshaft.

In the future I think I'll start just fletching up all arrows with the same color vanes and then just nock tune them afterwards.

 

[MattB]

It would be really interesting to have someone assemble a dozen arrows with FBBH’s with no consideration to nock tuning, shoot them, and measure the group size. Then nock tune and repeat, and determine the % decrease in group size.

 

[sickles107]

It would be really interesting to have someone assemble a dozen arrows with FBBH’s with no consideration to nock tuning, shoot them, and measure the group size. Then nock tune and repeat, and determine the % decrease in group size.

Fbbh?

From what I have seen, talking a bow tuned to one bare shaft, clocking four differnt nock "settings". usually one setting produces about a 1" tear vertical tear, then another produces about 1" horizontal tear, then there is two setting pretty close. all depending what position you tune your bow to.

In theory, if you did not consider nock tuning ("spine indexing"), and tuned your bow to shoot clean tears with "arrow 1" in position "x-best setting possible", and say arrow 2 was in position "y-worse setting possible", arrow 2 could produce a 1" tear horizontal, vertical, or both.

I think there is alot of variables to how that would print on a target at 40yd. More fletching drag may correct it more, more point drag (bigger broadhead) may plane off more.

 

[Jon_G]

Fbbh?

Fixed blade broadhead

 

[5MilesBack]

I’ve read here a good bit about nock tuning, but don’t remember folks ever mentioning how big the group sizes were before or after.

For me it's not a group size thing.....it's how far off the line I'm aiming at that some arrows will hit. My nock tuning is always with fletched arrows, and always shooting at a vertical line and/or horizontal line. >9 times out of 10 I'll only see left and right differentiation and rarely vertical when nock tuning. But it's common for me to see one or two arrows out of a dozen that will consistently hit 2" left or right of the vertical line from 40 with just FP's. After some nock tuning they'll always start hitting the line. Maybe 1 or 2 in the last 15 or so years that just wouldn't hit the line with the others no matter what I did to them. Those got relegated to arrow and BH testing duty and shot into steel drums and the like.

 

[Jon_G]

For me it's not a group size thing.....it's how far off the line I'm aiming at that some arrows will hit. My nock tuning is always with fletched arrows, and always shooting at a vertical line and/or horizontal line. >9 times out of 10 I'll only see left and right differentiation and rarely vertical when nock tuning. But it's common for me to see one or two arrows out of a dozen that will consistently hit 2" left or right of the vertical line from 40 with just FP's. After some nock tuning they'll always start hitting the line. Maybe 1 or 2 in the last 15 or so years that just wouldn't hit the line with the others no matter what I did to them. Those got relegated to arrow and BH testing duty and shot into steel drums and the like.

And this is done at 40 yards?

 

[5MilesBack]

And this is done at 40 yards?

I do, yes. I rarely shoot less than 40. And it's real easy for me to hold steady on a single plane....i.e. vertical line, so the shot always breaks well on target.

 

[Jon_G]

I will try this. Thank you