# Tuning a compound bow with a cushion plunger



## Finger_Flinger (Mar 25, 2009)

I have been meaning to retune my bow as it's been off since tearing down the bow and using the sight rest etc. on a Brigadier I had for awhile.

Including setting tiller, what steps should I take in order to tune my bow? I shoot a 99' Reflex Caribou II @ around 67-68# @ 29" draw or slightly less. I'm shooting 28.5" 2219's with 3 5" left wing helical feathers. I had been using 150 grain field points, but, it seems they're weakening the arrow too much. I'm now going to attempt to tune with 125 gr. points. I'm shooting with a NAP Plungerest. 

I seem to get hung up on bareshaft tuning v.s. paper tuning. Last summer, I had my bow walkback tuned to 40 yards and could group very well, but, try a bareshaft @ 20+ yards and it would impact the target sideways.

Anyone have TAP or anything that would help?

Let the suggestions begin!


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## Harperman (Sep 3, 2006)

Finger_Flinger said:


> I have been meaning to retune my bow as it's been off since tearing down the bow and using the sight rest etc. on a Brigadier I had for awhile.
> 
> Including setting tiller, what steps should I take in order to tune my bow? I shoot a 99' Reflex Caribou II @ around 67-68# @ 29" draw or slightly less. I'm shooting 28.5" 2219's with 3 5" left wing helical feathers. I had been using 150 grain field points, but, it seems they're weakening the arrow too much. I'm now going to attempt to tune with 125 gr. points. I'm shooting with a NAP Plungerest.
> 
> ...


.....Finger Flinger.....Do a Google search for "Tuning for Tens"......If You find it, and follow the instructions, it will show You how to tune a bow for optimum arrow flight......Excellent read.......Hope this helps......Take care!.........Jim


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## Finger_Flinger (Mar 25, 2009)

I've seen the "Tuning for Tens" PDF, but, the first step, setting the arrow inline with the center or the limb/string does NOT set the centershot on a compound, correct? My energy wheels do not align the string down the center of the limb, but, slightly to the left on a right hand bow.


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## rambofirstblood (Jan 11, 2010)

After initial rest setup, arrow tip slightly left of string at rest, I always check for proper clearance. I spray my arrow with powder and shoot. I must have 100% clearance before i proceed any further. I'm sure you know this, just trying to help.


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## fingers (May 27, 2002)

Go with the bare shaft tuning. You said the arrow went sideways, which way? Tune it to go straight. More poundage to lean right, less to lean left. Straighten it out and then back up and fine tune to 40yds.


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## Unclegus (May 27, 2003)

fingers said:


> Go with the bare shaft tuning. You said the arrow went sideways, which way? Tune it to go straight. More poundage to lean right, less to lean left. Straighten it out and then back up and fine tune to 40yds.


well said......


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## Finger_Flinger (Mar 25, 2009)

I'm pretty sure the arrow impacted nock left, which would indicate a stiff arrow? Perhaps, I should stay with my 150 grain points. 

The other thing I've never tried is using something, a matchstick or small nail, to completely stiffen the plunger. In the next week or so I'l be tinkering to tune this bow up again.


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## Finger_Flinger (Mar 25, 2009)

I tinkered more today, which seems to happen once I start. I'm shooting my bareshaft 2219's @ 28.5" w/ 125 grain points. I turned my bow down to 61# using my hand held spring scale. I believe the scale is about 3 #'s off, so I'm guessing it's @ 64#'s.

I've only shot @ about 10 yards in the basement, but, I finally got the shafts straight. It seems my arrows were pretty weak since I was shooting about 3#'s more with 150 gr. field points. I'll probably keep a log on here until I have this bow dialed in to perfection.


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## Finger_Flinger (Mar 25, 2009)

Anyone have TAP or a similar program?


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## CutTheLoop (Dec 26, 2007)

Haven't shot a plunger since about 1982... can y'all recommend a good one.

Been wanting to try one on a compound out of curiosity.


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## Finger_Flinger (Mar 25, 2009)

When I say plunger, I actually mean NAP Plungerest. The most popular is probably the Cavalier Free Flyte w/ Master Lok Plunger.


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## Finger_Flinger (Mar 25, 2009)

I really would like to use my 150 grain field points. Do you think I could use a 2315 or 2317?


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## rambofirstblood (Jan 11, 2010)

Do you build your own arrows? You could buy a few 2315 shafts and play with them and see if you can get them to tune with the 150 grain points.
You seem to like to tinker.


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## Finger_Flinger (Mar 25, 2009)

I do build my own arrows, with the exception of cutting.


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## biblethumpncop (May 14, 2004)

For a right handed shooter, if the bareshaft shot to the left of the group, it would have a nock right and be stiff. If the bareshaft shot to the right of the group, it would have a nock left and would be weak.


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## rambofirstblood (Jan 11, 2010)

Finger_Flinger said:


> I do build my own arrows, with the exception of cutting.


I think your next new toy should be an arrow saw. It's nice to be able to adjust arrow length for testing, and build your own start to finish. Unless of course you live over a pro shop.


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## Finger_Flinger (Mar 25, 2009)

Should I get a 2317 or 2315? When I look @ the chart, it says a 2219 @ 28.5 " should be stiff enough, but, it seems it's not. A bareshaft 2219 flies straight @ about 64# with a 125 grain field point. I'm leaning towards a 2317. I DO intend on using a 150 grain point. 

Thanks!


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## arrowshooters (Jun 5, 2006)

Is this what you were doing? This is what my bare shafts do from 17 yards, but I am "spot" on out to 60 with the fletching. Looks funny huh.

As for lining up your center shot, measure from the side of your limb to the center of the string at the cams then mark this measurement on your limb just above the riser. Do this on both sides. It will be much easier to line up the string to these marks. Set you arrowrest so that you see about half the tip outside the string. 

This is where I differ from most others: I do not paper, walk-back or bareshaft tune. (I just happened to have a couple of shafts handy when I had a buddy over to prove a point, hence the pic.) Screw the tension adjuster almost all the way in on your plunger. Now use the marks on your limbs to line the string and your sight pins. 

Now go shoot your bow. Start close to be sure you're on the target then go back to about 10 yards. You should be hitting left (right hand shooter). From here, start reducing the tension on your plunger spring and you will see your arrow start moving to the right. Adjust until you start hitting right then tighten it back again until you are in the bull. 

That's it, the rest is up to you and your release/form. Most people go crazy with the tuning stuff when the problem is really them. Oh, your 2219's with the 150's should be fine up to your 68#, better with the 125's though.


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## Finger_Flinger (Mar 25, 2009)

I just received some 2317 XX78's via the classified ads here. I'm gonna make the 1 hour trip to Terminal Velocity Archery to get her tuned up. If I cut the 2317's to 28.5" with 3 5" feathers & 150 grain points, these arrows should spine damn near perfectly with my 'Bou II set @ 28.75" & 67# according to TAP.

I can't wait to get this sucker set up & begin shooting daily again.


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## Bruce K (Jun 1, 2002)

Just a quick question , what distance do you bareshaft tune at , my lightspeed 400's hit around 1.5 inch left of my group at 20 yds , should I wind the bow down a little to get the arrows hitting inside the group at 20 yds or do I need to do it at longer distances ?


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## dragonheart (Jul 18, 2008)

arrowshooters said:


> Is this what you were doing? This is what my bare shafts do from 17 yards, but I am "spot" on out to 60 with the fletching. Looks funny huh.
> 
> As for lining up your center shot, measure from the side of your limb to the center of the string at the cams then mark this measurement on your limb just above the riser. Do this on both sides. It will be much easier to line up the string to these marks. Set you arrowrest so that you see about half the tip outside the string.
> 
> ...


How do you set up your nocking point?


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## fingers (May 27, 2002)

I'd like to throw out a challenge for anyone who is good at bare shaft tuning so as to make a point. Set the bow up as you feel is right and then bare shaft tune until you get good flight at 20yds. Now move your rest out to the left and watch what it does to your arrow flight(bare shaft) and now do the opposite direction. How does the arrow fly? I'm not talking about where it impacts, I'm talking about how it flies. The reason I feel this is important is to show that the force imparted on the arrow is the determining factor on straight flight. By moving the rest in or out or upping or dropping tension on the plunger button, the main reaction to the arrow is where it impacts, not the flight itself. As far as forgiveness goes, well yes I think rest position does make a difference. But it is best to first set the correct poundage for that arrow, make it fly straight, before you go tinkering with all that fine tuning. It keeps things simple.


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## arrowshooters (Jun 5, 2006)

dragonheart said:


> How do you set up your nocking point?


About 5/16" up from rest level which is about 1/8" up from top of nock with arrow level.


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## AKRuss (Jan 10, 2003)

I setup centershot by eyeball or EZE EYE laser and than adjust the plunger tension. If things are pretty close you can walk the point of impact back and forth across the target by adjusting spring tension. Adjusting centershot seems like a more coarse tuning technique that I generally do before playing with spring tension. Just my opinion or MO. The proof in tuning is grouping at long range.


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## jerrytee (Feb 5, 2005)

Down load the Easton Tuning guide. set your plunger/button tension about mid point. Set the center shot so that the arrow is about 1/4 of its diameter point outwards and shoot. First of all correct the nocking point height. Then shoot again. If you are RH then arrow left = stiff arrow right = weak. Do not alter two things at once. trim the poundage of the bow til you get the bare shaft in with the other arrows. Then fine tune with the button spring tension, stiff arrow weaken the spring tension. Then do a walk back tune to check the center shot, If you have to change the center shot ,then check the bareshaft tune again. You may have to alter the button spring tension.


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## rogerwatkins (Mar 9, 2010)

*bare shaft tuning*

using chuck adams old book adjust bare shafts up down left right as far back you shoot good now add hunting arrows adjust draw wt.1/4 turn upand shoot for groups keep going up until you best group this offset wt.diff.


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## bigbob29 (Sep 7, 2009)

*bareshaft tuning*

Have been bare shaft tuning my ol' cougar elite and find that it shoots best with what amounts to a virtual true centre shot with arrow alignment, in other words string 'splits' the arrow.Also plunger tension is wound right in so barely any 'button' showing on plunger barrel.I am of course a finger shooter.With this set up can put 2 out of 3 bare shafts in a 2'' dot at 20 metres and acceptably accurate out to 40m.Actually more accurate with them than fletched arrows at 20m , and I have checked clearance issues with the vanes. No marks on vanes nor any in powder, so who knows? Does this set up seem weird to you guys? I shoot 340 powerflights with AMO of 31 and 125g target points. The cougar is set on 56lb, and am using 4'' vane tec vanes [3 of] Bob


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## bigbob29 (Sep 7, 2009)

Am I a thread killer?:darkbeer:


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## dragonheart (Jul 18, 2008)

"down the middle" with center shot is common for me also. I like a softer button, just seems more forgiving of shooting errors.


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## bigbob29 (Sep 7, 2009)

thanks dragon heart,
By softer button that would mean you have more extended or more sticking out past body of plunger -right? Until I got this cougar last year all I ever used for several decades was the old stick on flipper type and shot preeety good with them so being able to tune the rest ala berger or plunger is a luxury for me. Regards to all the great guys on this forum.


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## dragonheart (Jul 18, 2008)

The tension on the plunger is softer or "easier to compress". I do not like a really stiff berger button.


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## rogerwatkins (Mar 9, 2010)

read all input some good some bad 1,check bow draw lt.you may not bedrawing to astop,2used plunger 20plus years ishoothoyt vantage,at 64lbs.2216,29in, w/125 heads this workswell for me draw lt.28.5 also agree that chucks old book on bare shaft tuning is a good start


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## bowcycle (Aug 26, 2011)

rogerwatkins said:


> read all input some good some bad 1,check bow draw lt.you may not bedrawing to astop,2used plunger 20plus years ishoothoyt vantage,at 64lbs.2216,29in, w/125 heads this workswell for me draw lt.28.5 also agree that chucks old book on bare shaft tuning is a good start


Wow! Am I going to be the first one to say it? Dude, this thread is over a year dead! Please check the date before posting.


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## zestycj7 (Sep 24, 2010)

I have my arrows flying like darts, but if I try shooing a bare shaft at 20 yards it will end up in the next county. It takes a heck of a dive low left then it's skyhigh to the right and out of sight.
What would cause this?
At abut 10 yards the shaft if sticking in the target from the bottom left facing the right.
Don.


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