# bare-shaft and walk-back tuning don't agree; what to do?



## rascal650 (Aug 7, 2012)

I’m getting inconsistent results between my bare shaft and walk-back tuning. Any help from the experts (Limbwalker / Vittorio / others???? ) would be appreciated.

Here is some info about my setup:
- LEFT handed shooter; results are inversed (“left is right and right is left…”)
- I checked the limb alignment. Off center is fine (1/2 of the arrow diameter showing on the right side of the string)
- Beiter plunger; medium spring, tension right on the “5” (middle of thread) 
- 70” bow, BH: 9.25”
- about 40# at the finger
- arrow: MCKII 550, 30.5” (BOP), 100gr points​

First, I get my bow tuned with “bare shaft” at 18 then 30m (primarily by adjusting the limb bolts). Then, when I move to the walk-back tuning, I find that my arrows go more and more to the right at the longest distance (indicating stiff for LH). As suggested, I end up softening the plunger tension but I end up doing lots of turns to get the arrows to fly straight at 30M, 50M, 70M (have not tried 90M yet). 

After decreasing the plunger tension, when I go back to bare shaft tuning at 30M, the bare shaft goes way to the left (from 12" to 20”, depending on the decrease in plunger tension), indicating weak for me. I even tried the soft spring in my plunger (to get back to the middle of the plunger thread) but I get the same results. 

I tried to change the off-center (in both direction) but I noticed that the arrows tend to hit the target at a less than optimal angle. I still could not get a perfectly "straight" walk-back result right after my "bare-shaft" tune.

One more bit of info, I’ve had this problem for quite some time now, with different kind of arrows ( carbon one 550 , ACE 570, and now with MCKII 550). I suspect my form / release have something to do with that.

Is that easy for you guys to get the bare-shaft and walk-back tunings working perfectly together?

If I can’t get both to work, should I focus on the bare shaft tuning and accept that I will get different horizontal sight marks for 30, 50, 70 and 90m? 

Thanks for your help!

Pascal


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## Joe T (Apr 5, 2003)

First thing I would check is the windage setting on your sight pin. How far in/out the pin is screwed won't make any difference to the bare shafts grouping with the fletched arrows but will make your arrows go left/right as you change the target distance.

Zeroing a sight is something quite important but rarely given any attention. Don't know how the "pros" do it.
Personally I just shoot at a vertical line at around 10-15 yards and just the windage to put the arrows on/around the line. The rationale is that over a short distance the arrows aren't going to much much sideways so the pin ends up in the position where it's pointing in the direction the arrows are leaving the bow.


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## theminoritydude (Feb 11, 2013)

Ignore the bare shaft. You're not going to score with them, so why do they matter when your walk back tune says your fletched arrows are alright?


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## Eolla (Jan 19, 2005)

Check your sight bar is straight. tape a business card to the edge and check it against the string line. a slight skew in the vertical sight bar will effect where your land as you walk back


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## Mika Savola (Sep 2, 2008)

You don't move your sight when walk-backing


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## theminoritydude (Feb 11, 2013)

Wait, he adjusted his sight?


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## cc46 (Jan 22, 2005)

I usually do a bare shaft tune first at a short to medium distance. 
Then do a walk back test, say 18m to 40m, without moving the sight. If the walk back test reveals a slanted fall in the arrows on the target, like / or \, I then adjust centre shot. I don't touch the plunger at this point. 
Now with centre shot adjusted I do a bare-shaft tune again to see if the plunger needs to be softened or stiffened. If so I adjust minimally. 
Then do a walk back test again. Usually all is good so I stop. If there is still a slant I minimally adjust


Also I've found, with equal nocks, vanes and pins that ACE 570s w/100gr points equate to MKII 650s with 110gr points when I tune.


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## rascal650 (Aug 7, 2012)

Yes, I forgot to mention that I checked (with a bubble level) that my sight and string are perfectly vertical while my bow was on my dip bar....

No, I did not touch the sight during the walk-back tuning. But at this point, I think I would have to get different horizontal sight marks for my next FITA tournament because I ended up with a plunger tension that's way too soft.

Joe T: The inner frame of my aperture is currently aligned with my arrow shaft, so the aperture center is a bit on the outside but not by much. I believe it's a quite common position. I'll see how the aperture position affects my tuning next time I'm at the range.

cc46: In my case, I would have to move the center shot IN (since the arrows are showing the \ pattern, for LH), correct? It's already so close to the center shot. When I move it closer (almost in-line with the center shot), the arrow tails start to kick out (to the right for me).


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## c365 (May 15, 2013)

http://texasarchery.org/BoardMembers/RickStonebrakerPages/TuningForTens/TuningForTens.html


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## theminoritydude (Feb 11, 2013)

I read your specs. Increase point weight to 120gr, ensure that the arrow is not too long (about 1 inch between cut off of the shaft to the button should suffice.

My simulations indicate a sort of false reading from your bare shaft due to the high frequency of your shaft as a result of your low point weight. And some other mumbo jumbo but, just try that first.

I still maintain that you should ignore bare shafts after you have initiated the walk back tune.


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## theminoritydude (Feb 11, 2013)

Also, your arrows are scraping your plunger housing....


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## rascal650 (Aug 7, 2012)

Thanks for you input, "minoritydude"....

What tool do you use for your simulations?

I have just below 1" of shaft in front of the plunger. I went with 100gr because Rick McKinney recommends 80-100gr for the McKII 550  (remember the MCKII shaft is so light, you still get a high FOC with a 100gr point). FYI: My total arrow weight (>31" with point) is around 290gr. I'll try to increase the point weight soon and see if I can see a behavior change.

I went back to a medium tension (medium spring / thread right on the "5") because my group widened significantly with a very soft tension. With the medium tension setup, I get a very decent bare shaft tuning (all arrows in the 8 ring on 40cm at 18m) and similar at 30m (all arrows in red on 80cm, which for my level is all I can get). At this point, all seems fine but I need 4 different horizontal sight marks for my 4 FITA distances. Between 90M in 30M, I estimate I need 4-5 full turns (maybe 1/2 the horizontal range, maybe more). 

With medium tension, I doubt that my plunger is bottoming out. Do you think my arrows are too stiff, slam the plunger on release and show a "false-positive" weak result? The flight path looks pretty straight (for bare and fletched shafts) at all distances (even when I should in my cube from 5 feet away).


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## grantmac (May 31, 2007)

What position do you keep the stringblur in?

-Grant


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## rascal650 (Aug 7, 2012)

I keep it on the very edge of the riser (the edge closest to the aperture).


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## theminoritydude (Feb 11, 2013)

rascal650 said:


> Thanks for you input, "minoritydude"....
> 
> What tool do you use for your simulations?


A very antiquated neural-network device built in the 70s that runs on grains and stir fry. I recently experimented with salads and lean meat with varying results.

That aside, I was a user of the CT shafts about 12 years ago, though they weren't McKinneys, at 120gr and 42lbs I had very tight groups. Although I couldn't remember which spine I was using, I do not believe in an upper limit for point weight based on recommendations that are not a result of 1)the maximum distance achievable, 2) maximum distance engaged, 3) optimal impact angle on the target, 4) adjustment margins for headwind and crosswind, 5) range inclination angle.


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## Cplev (Feb 16, 2012)

When I do walk back tuning, I change the plunger depth, not the tension. I change tension with bare shaft tuning only


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## Joe T (Apr 5, 2003)

Had a play with my Drift simulator on this (though I used ACE-570 shaft as don't have the details for the MK shaft).
If as you say the bare shafts at 30m distance /80cm target are hitting outer red (~20cm off) then your fletched arrows at 70m could be sideways in the black. So there is no conflict between the two results. Basically your bow isn't well "tuned". With 30m bare shaft method you need the group no larger than the gold with the fletched in the ten. 

I would suggest:
a) resetting center shot, spring pressure etc to the default values. i.e initial basic set up (this includes re-zeroing the sight windage - pin above arrow shaft probably near enough)
b) At 20 yards adjust the draw weight so that the bare and fletched shafts hit as close together as possible (target - ideally within a couple of inches of each other)
c) Go to the longest distance you can group reasonably well at. Shoot a bunch of fletched arrows and note the position of the estimated group center relative to the gold center. Move the group center towards the target center by changing the button spring tension (with LH if the group is left increase spring tension and vice versa). Repeat as necessary to get your arrow group centered on the target center.
d) Without changing anything other than the vertical pin position you can If you like move to a closer distance to check that the fletched arrows still group around the target centre (this the walk back check).

My own experience is that starting with a good basic set up (draw weight), if you get the arrows to fly straight using spring tension adjustment (walk back method) then if you shoot at 30 meters, with the fletched arrows hitting the target center the bare shafts will be in the red on an 80cm target. Not brilliant perhaps but you can only tune as well as you shoot.

If you get nowhere at step c) try changing the center shot in the appropriate direction (LH increase center shot to move group left and vv) and start again from a) or you might get away with just starting again from c)


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## Joe T (Apr 5, 2003)

"If you get nowhere at step c) try changing the center shot in the appropriate direction (LH increase center shot to move group *right *and vv) and start again from a) or you might get away with just starting again from c)"

Some days I can't tell left from right..duh!


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## theminoritydude (Feb 11, 2013)

If you wanna have a simple start, shoot a dead plunger with centreshot and alternate between fletched and bareshaft. Adjust the bow's poundage until the two group together at 30m. Once you have achieved that, set a medium spring tension, and give your plunger one full turn to the right, and begin your walk back tune from there.

If you couldn't get past the first stage with the bareshaft, you may want to look at choosing a different spine, and the difference between the bareshaft and fletched arrows will tell you to spine up, or down.

May I request that you post a picture of your bow with the string lined up with the centre of the grip throat, with the end of the long stabilizer visible? Thanks.


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## limbwalker (Sep 26, 2003)

Cplev said:


> When I do walk back tuning, I change the plunger depth, not the tension. I change tension with bare shaft tuning only


^^^ This.


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## Joe T (Apr 5, 2003)

limbwalker said:


> ^^^ This.


Note: that CC46 has already done a bare shaft tune before doing the walk back so the button spring already adjusted. In this case I agree.

If no bare shaft tune before the walk back then I would recommend using the button spring for adjustment. Center shot adjustment is plan B if the spring can't do the job.

CC46's suggestion pretty much the same as mine i.e setup(draw weight) -> bare shaft (spring tension) -> walk back (center shot)->reiterate as required.


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## kilerhamilton (Jul 19, 2010)

Practice shooting not tuning. If it walk back tunes then group tune it. 

Make sure stops are hitting together, you like your draw lenght and weight. Put D-loop on 90* to rest at burger hole and let em rip. 

If your shooting fixed blade broad heads then you have a problem. Until then don't sweat it.


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## theminoritydude (Feb 11, 2013)

kilerhamilton said:


> Practice shooting not tuning. If it walk back tunes then group tune it.
> 
> Make sure stops are hitting together, you like your draw lenght and weight. Put D-loop on 90* to rest at burger hole and let em rip.
> 
> If your shooting fixed blade broad heads then you have a problem. Until then don't sweat it.


Recurve.


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## Astroguy (Oct 11, 2013)

I think its time to paper test 5ft away from the riser. 

I also shoot left, If you can get a nock tear slightly ( 1 shaft ) up and outside at 45 degrees, on an average release and bulletholes on great release. Your tuning will go much better. 

And see if you are stiff or weak out of the bow. I have seen changes from swapping a finger tab. 

Plumb your riser and sight bar together before tuning to save time later. Once you walkback test well. Very minor ( 1/8th turn ) spring plunger adjustments will help to square up at longer distances. 

Start your centershot slightly outside so the tip of your arrow is just outside, to match where the string rolls off your fingers.

I think you need more point weight and more fletching from what I have read so far.


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## Astroguy (Oct 11, 2013)

I should add that when my walkback or French tune is right. My paper test is slightly high to the outside of the riser. Never tearing on the riser side.


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## Seattlepop (Dec 8, 2003)

I always found this works well in walk-back tuning for recognizing what needs adjusting, button pressure and/or center-shot:

View attachment 2161185


(Source: "Reference guide for recurve archers", The latest edition of this document may be downloaded from:
http://www.archersreference.co.uk/download.html)


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## Mika Savola (Sep 2, 2008)

Seattlepop said:


> I always found this works well in walk-back tuning for recognizing what needs adjusting, button pressure and/or center-shot:
> 
> View attachment 2161185
> 
> ...


+1 

...


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## Astroguy (Oct 11, 2013)

-1 He shoots left handed.

Do the paper test 5 ft out of the bow and see if you have a spine you can work with before overthinking.

Sometimes you can add point weight to help a stiff arrow. But a weak arrow cant be helped as much.


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## c365 (May 15, 2013)

Seattlepop said:


> I always found this works well in walk-back tuning for recognizing what needs adjusting, button pressure and/or center-shot:
> http://www.archersreference.co.uk/download.html)


That's why I suggested doing a systematic approach like Tune for Tens is another one. Otherwise it's a time consuming, don't get anywhere hit and miss affair messing with the plunger in/out, spring tension etc. guesswork.


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## c365 (May 15, 2013)

Astroguy said:


> -1 He shoots left handed.
> 
> Do the paper test 5 ft out of the bow and see if you have a spine you can work with before overthinking.
> 
> Sometimes you can add point weight to help a stiff arrow. But a weak arrow cant be helped as much.


That's right, I always get the spine just right by bareshafting first before even thinking of anything else.


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## Seattlepop (Dec 8, 2003)

Astroguy said:


> -1 He shoots left handed.
> 
> Do the paper test 5 ft out of the bow and see if you have a spine you can work with before overthinking.
> 
> Sometimes you can add point weight to help a stiff arrow. But a weak arrow cant be helped as much.


RE left handed...I assume he is smart enough to adjust accordingly. 

But more importantly perhaps and for the record, you and I are probably the only two people on AT who believe recurve paper testing can be productive. :thumbs_up


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## TheArrow (Dec 14, 2014)

Is walk-back tuning the only (or best) way to differentiate between a tuning issue with plunger depth vs spring tension? For example, a buddy of mine was shooting last week at 20 meters. His flectched and bare shafts were hitting together, but his group was to the right of the gold. In this case, assuming it's not the archer or some undesired physical contact, three things come to mind, his sight windage, plunger depth, and spring tension. His sight alignment to the string was spot on to the right side of his aperture. I feared having him adjust the plunger, because what might work at 20 meters may not work at another distance.

Also, a question that's been nagging me. Isn't plunger depth similar in arrow reaction to nock adjustment? If the nock is high or low, you'll get porpoising and the bare shaft will hit high or low of the fletched arrows. Wouldn't the same be true of plunger depth, just in the horizontal plane? Hence in the scenario above, since his bare shafts hit with the group, does that indicate proper plunger depth (centershot) or just that it works at 20 meters?


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## Joe T (Apr 5, 2003)

TheArrow said:


> Is walk-back tuning the only (or best) way to differentiate between a tuning issue with plunger depth vs spring tension? For example, a buddy of mine was shooting last week at 20 meters. His flectched and bare shafts were hitting together, but his group was to the right of the gold. In this case, assuming it's not the archer or some undesired physical contact, three things come to mind, his sight windage, plunger depth, and spring tension. His sight alignment to the string was spot on to the right side of his aperture. I feared having him adjust the plunger, because what might work at 20 meters may not work at another distance.
> 
> Also, a question that's been nagging me. Isn't plunger depth similar in arrow reaction to nock adjustment? If the nock is high or low, you'll get porpoising and the bare shaft will hit high or low of the fletched arrows. Wouldn't the same be true of plunger depth, just in the horizontal plane? Hence in the scenario above, since his bare shafts hit with the group, does that indicate proper plunger depth (centershot) or just that it works at 20 meters?


You have three goals with the whole setup/tuning routine. you want
a) The arrow to flex nicely around the riser having clearance while leaving the string cleanly.
b) The arrow to leave the bow aligned in the direction it is traveling (what's called zero angle of attack)
c) you want the arrow to be rotating (not be confused with the fletching spin) at the best rate and direction in terms of minimizing arrow groups (called angular velocity)

You have get all three things right at same time (which like flat pack furniture requires you to have three hands). The logical approach to this is to keep as many variables as possible fixed and then dedicate the minimum number of variables to each of the three items above. If you don't do this you end up going round in circles for ever. A popular approach is:-
for a) adjust the draw weight 
for b) adjust the center shot
for c) adjust the button spring tension.

and never cross link these variables e.g. don't adjust both center shot and spring tension to do the same thing (even if you can)

The arrow shaft is only in contact with the button for a very short time at the very beginning of the power stroke so plunger depth does not directly affect the direction the arrow leaves
the bow. It will indirectly affect where the arrow ends up directionally via mechanisms a), b) and c). All the different variables have to be together in sync to get a,b, all ok at the same time.


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## TheArrow (Dec 14, 2014)

Joe T said:


> You have three goals with the whole setup/tuning routine. you want
> a) The arrow to flex nicely around the riser having clearance while leaving the string cleanly.
> b) The arrow to leave the bow aligned in the direction it is traveling (what's called zero angle of attack)
> c) you want the arrow to be rotating (not be confused with the fletching spin) at the best rate and direction in terms of minimizing arrow groups (called angular velocity)
> ...


Thanks Joe! I initially helped him adjust his bare shafts to hit with his fletched arrows by adjusting his draw weight. You mentioned that the next step is typically center shot. What's the recommended method for that at this stage (where his groups are hitting to the right of the gold)? Would you say that walking back and looking for the patterns posted by Seattlepop is the best way to go? Is it the only way?


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## rascal650 (Aug 7, 2012)

Thanks Joe. What is an easy/objective way to measure that you have achieved b) & c) (or at least you are headed in the right direction)?

I assumed a) is done by making sure your bare shaft is grouping with your fletched arrows at 18 / 30M. Correct?


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## Joe T (Apr 5, 2003)

The actual order is a c b
a is bow setup - draw weight adjusted to put bare & fletched together at 20 yards
c is 30 Meter bareshaft - button spring & nock point to adjust arrow rotation
b is walk back to adjust centre shot - arrow alignment (zero attack angle )

a & c you can find lots of places
For b see "the simple art of winning"


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## TheArrow (Dec 14, 2014)

Thanks again Joe! You've been a great help. Now if you could just do something about the weather report (Freezing Rain) this weekend, so that I can put your advice to use.


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