# Tuning with Beiter plunger with bareshaft



## rambo-yambo (Aug 12, 2008)

I tried to do bareshaft tuning with fletched arrows and bareshafts at 20 yards with my new Beiter plunger. Both sets grouped nicely by themselves but the 2 groups are not grouped together. 1 thing I noticed is that the fletched arrow go in straight but the bareshaft go in at an angle. Adjusted plunger pressure helped a little bit but did not solved the problem. Is this caused by my release, plunger pressure or something else. (Draw weight is about 30# on my finger with 810 ACG shaft cut to 27" with 110 gn point, 225 plastifletch. I used Beiter plunger with a light sping and setting on the plunger was around 5.5).

Also, I was able to adjust plunger knob without having to push a spring loaded button at the end of the plunger. I was told by another archer that he has to push the end button down to adjust the dial. Did I install the plunger wrong? Are the 2 things above related? Thanks


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## archerynooblol (Nov 6, 2010)

Unless I'm terribly mistaken, you don't need to push that button on the end. I've never done it on mine. 

I think all it does is keep the spring concentric in the plunger barrel. 

Pretty sure from a manufacturing standpoint, it's easier to drill straight through and stick the back button into the plunger than machine something on the inside of the plunger for the spring to rest on.

The premise of the adjustment is that when you tighten the barrel it shortens the length of the plunger, which adds preload to the spring. This shifts which increases the force of the spring as diagrammed below:









AN


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## lksseven (Mar 21, 2010)

the plastic button end sticking out of the back of the plunger doesn't have anything to do with the adjusting dial (at least, my Beiter doesn't). I think it's there so you can press it with your finger to get a tactile feel of how much resistance you've set the plunger button for (at least, I use it for that).

If you're right handed: 
To converge groups:

If the bare shaft group is to the right of the fletched group, then you can bring those groups together by lowering the draw weight (turning limb bolts out, or decreasing draw length). If bare shaft group is hitting to the left of fletched group, then increase the draw weight (turning limb bolts in, or increasing draw length)

To get bare shafts to strike target at same angle as fletched:

If bare shafts are nock left (nock is to the left of the point), then adjust centershot by adjusting the plunger housing to push the arrow away from the riser, stiffening the dynamic spine (or, if bare shafts are just a slight angle, then you might first try making the button a little bit stiffer, or lowering your brace height a little). If bare shafts are nock right (nock is to the right of the point), then adjust centershot by adjusting the plunger housing inward so that the arrow is closer to the riser, which will weaken the dynamic spine. And again, if the entry angle is only slight (and you don't want to increase your draw weight), you might first try making the button a little bit weaker, or raising your brace height a little

In other words, move the point in or out by adjusting centershot ... if the point is to the left of the nock, pull the point in by pulling in centershot. If the point is too far right, push the point away from the bow by pushing out centershot.


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## rambo-yambo (Aug 12, 2008)

lksseven said:


> the plastic button end sticking out of the back of the plunger doesn't have anything to do with the adjusting dial (at least, my Beiter doesn't). I think it's there so you can press it with your finger to get a tactile feel of how much resistance you've set the plunger button for (at least, I use it for that).
> 
> If you're right handed:
> To converge groups:
> ...


I shoot LH and bareshafts grouped to the right of the fletched shafts means the arrow spline is too light. I reduced the plunger pressure and was able to bring the group closer but the 2 groups did not converge. By lowering the plunger pressure to minimum, my group within fletched arrows started to spread apart. 

my bareshafts are nocked right means I should adjust the arrow away from the riser. If I do, the centerline of the arrow will be way off.

Question #1: should I adjust centerline first before plunger adjustment or after plunger adjustment? Which setting is more important? (I adjusted centerline first)
Question #2: With a 110gn point on a 810 spined ACG cut to 27", is the arrow about the correct spine for a finger draw weight of 30#? Should I go with a heavier point weight?
Question #3: Can point weight affect how the bareshaft nocked?
Question #4: How important is bareshaft not going straight?
Question #5: How important is it to have the 2 groups (fletched and bareshaft) converged? (I read somewhere that the 2 groups (bareshaft and fletch) do not have to converge as long as I get the best grouping with fletched arrows - is it correct?)
Question #6: Are these all related? Can it be solved with a single fix? 

Thanks,


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## HikerDave (Jan 1, 2011)

Bare shafts grouped to the right for a left-handed archery means that the arrows are acting stiff.

You should probably start over, especially because your arrow flight is very strange.

Did you adjust your nocking point height first?

How is your release?

Is your bow in plane? My Hoyt Excel is perfect, but they aren't all that way.


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## rambo-yambo (Aug 12, 2008)

HikerDave said:


> Bare shafts grouped to the right for a left-handed archery means that the arrows are acting stiff.
> 
> You should probably start over, especially because your arrow flight is very strange.
> 
> ...


How do you check if the bow is in plane? I have never tune my bow with bareshafts until now. The nock height is about right because both bareshaft and fletched shafts congverge. I changed from 80gn point to 110 gn and changed from Shibuya DX to beiter plunger at the same time so I am not sure is 1 affects the other. I think my release is decent. because the fletched shaft and bareshafts grouped nicely in 2 separate groups. I might want to start over to see if I can figure out. Thanks.


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## Mika Savola (Sep 2, 2008)

ACG 810 is just simply too stiff for your poundage and arrow length


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## w8lon (Jun 2, 2012)

With given shaft specs I am calculating your arrows would be ideal with 45# limbs, quite stiff. Did you cut all of your shafts? At 29" to BOP 810 ACG's should be very close.


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## HikerDave (Jan 1, 2011)

rambo-yambo said:


> How do you check if the bow is in plane? I have never tune my bow with bareshafts until now. The nock height is about right because both bareshaft and fletched shafts congverge. I changed from 80gn point to 110 gn and changed from Shibuya DX to beiter plunger at the same time so I am not sure is 1 affects the other. I think my release is decent. because the fletched shaft and bareshafts grouped nicely in 2 separate groups. I might want to start over to see if I can figure out. Thanks.


The Magera method of determining whether your bow is on plan is described in the thread below:

http://www.archerytalk.com/vb/showthread.php?t=1703779

Those two previous posters might be right and you might just have to get new arrows or up the poundage.


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## DWAA Archer (Oct 14, 2011)

For all the information you need for a good tune look here http://www.eastonarchery.com/img/downloads/software/tuning_guide.pdf 

I do my basic tune at 30m because at any distance less then that I do not seem to get a useful tune. Also I have been told that tuning at distances of less the 30m the arrow has not started to cycle properly.

My fletched and bare shaft group together at 30m although you can have your set up slightly stiff and nock point slightly high for a forgiving setup. When I do that the bare shafts land on the edge of the fletched arrow group stiff side same applies for nock height low edge of fletched group.

What my bare shaft and fletched arrow group will look like at 30m is all together in the 9-10 ring of a 60cm face at 30m thats a good tune for me and it seems to work well giving good groups at all distances. 

But what your groupings will look like is dependant on you ability so beginners or those that don't shoot very often or have poor form will give wide and or random results. Even with a totally mis matched bow a good archer can shoot groups if you cannot shoot groups tuning will be a waste of your efforts and time should be invested in form.

Shoot well.


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## horndog (Jan 5, 2009)

Mika Savola said:


> ACG 810 is just simply too stiff for your poundage and arrow length


I just ran it through Archer's Advantage, and agreed they are way too stiff!
1150 spine with 80gn points is in the weak side of the optimal range


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## rambo-yambo (Aug 12, 2008)

I am confused, I went to Easton site and used their shaft selector putting in 24-29# with arrow length of 27", Easton recommended ACG 810. But I was told my arrow is too stiff, can someone explain? Thanks,


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## horndog (Jan 5, 2009)

rambo-yambo said:


> I am confused, I went to Easton site and used their shaft selector putting in 24-29# with arrow length of 27", Easton recommended ACG 810. But I was told my arrow is too stiff, can someone explain? Thanks,


Open the latest Lancaster catalog and turn to page 37. There you will find a chart that I would suspect is not of Easton
origin. There you will find a different story. ACG @ 1150. You will have to make your own conclusions.


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## MickeyBisco (Jul 14, 2012)

Jacky,


Following the Easton charts, I've used ACEs, ACGs from 30#- 38# starting from 710/ 720 to 810 and 950... experimented with 1250s and back to 1000. When you cut these arrows down, they get a spine stiffer with every inch cut. 

I have 1000 spine ACEs, 26 7/8" groove to end of carbon. These BS tuned well at 30m, medium spring, Beiter plunger. Anything stiffer ( like my 720s) my plunger had to be absolutely mooshy to get the bare shaft to group.

I'm now holding 33#, and the 1000 spine/ 110 gn point is perfect for me. When I use my heavier limbs ( 38#) and its too weak I go to 100 or 90 gr.


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## limbwalker (Sep 26, 2003)

rambo-yambo said:


> I am confused, I went to Easton site and used their shaft selector putting in 24-29# with arrow length of 27", Easton recommended ACG 810. But I was told my arrow is too stiff, can someone explain? Thanks,


Only to confuse you further, my daughter shoots 23# on the fingers and 27" arrows and she is tuning 1500 spine CX Medallion XR's like a champ. 

Selecting arrows for light draw weights is a bit of a fine art...

What I have ALWAYS wanted to know the answer to, is why you get a completely different spine recommendation from the Easton Target chart and the Easton Youth chart for the same exact spec's. That makes NO sense at all. I mean, it's like 3 or 4 boxes off.


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## Vittorio (Jul 17, 2003)

limbwalker said:


> ...
> What I have ALWAYS wanted to know the answer to, is why you get a completely different spine recommendation from the Easton Target chart and the Easton Youth chart for the same exact spec's. That makes NO sense at all. I mean, it's like 3 or 4 boxes off.


This is one of the major misteries in archery ... never explained ... never discussed, never solved ... :smile:


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## Mika Savola (Sep 2, 2008)

Maybe it has the idea that "Youths" have lower efficient bows; too long limbs/too short arrow, dacron strings etc. Still to be determined the limits on what length of arrows and what poundage you can start believing the target chart...


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## limbwalker (Sep 26, 2003)

> Still to be determined the limits on what length of arrows and what poundage you can start believing the target chart...


Yup...

I've learned that there's nothing quite like putting an arrow on an 11 year-old's bow that will teach you how to select weaker spined arrows.

Same goes with new adult archers who are shooting in the low 20# range. 

That's where the rubber meets the road, and the charts are useless for anything but comedy relief.

There are still a whole bunch of JOAD archers, parents and coaches out there that think a 1000 spine is a "really weak" arrow when in reality, they should be using 2000 spine arrows...


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