Weird bareshaft results...any ideas?

[beachbowhunter]

ok, this one has me stumped.  I'm tuning arrows for a bow that shoots my existing hunting arrows quite well. They are:
CX Terminator 4560s (about 0.390 spine) cut to 29.5 with 225 to 250 up front.

I wanted a shorter, lighter arrow for this bow so I bought Victory 500s (0.500 spine), cut them to 29.5 to start. The bareshafts mostly hit where I'm looking when I get a good release, but the fletched arrows impact left (indicating stiff?).  Victory shafts are known for a high level of consistency in spine, straightness and weight. These are weaker shafts, so what gives?  

I've thought that they might be way weak but haven't cut one down more yet.  Any ideas?

[vermonster13]

Are you getting fletch contact with the riser?

[DesertDude]

Must be the bow Norb... Give it to me.....

[Dave Bulla]

What is your point weight on the new arrows?

[Whip]

I think you've got it right.  Here's the link to OL's tuning page.  Fletched arrows hitting left = weak.
  http://bowmaker.net/tuning.htm  

Or if that doesn't work, go with the "must be the bow" theory.  But send it to WI instead  

[JRY309]

What type of bow are you shooting?I had some used CX 45/60 that were cut at 29" and the were showing stiff on my longbow cut off center.So to weaken the spine I added more weight up front and the more weight I added the worse they were showing stiff.They were in effect bouncing off the riser instead of flexing around it.Maybe if they were longer they might have worked better.They may be alittle stiff for the bow.

[Bob L.]

If your old arrows are shooting well cut at 29" with 225-250 grains at 400 spine. With the exact same length and point weight the 500's will show weak because of the weaker spined shaft. You have 2 options without fooling with the strike plate. Less point weight or shorter arrows to bring those bareshafts over.
Bob

[freefeet]

Originally posted by beachbowhunter:
The bareshafts mostly hit where I'm looking when I get a good release, but the fletched arrows impact left (indicating stiff?).

If you're right handed then fletch arrows impacting left of bareshafts is indicating weak shafts.

Lower point weight to check before trimming your shafts.

[JC]

Fletched arrows tend to go straight...it's the bareshaft arrows that plane....so make your calculations based on where the bareshafts land in relation to fletched. So if your bareshafts are landing to the right of fletched, you have weak shafts...as long as the shaft is not bouncing off the riser. A suggestion, tune nock height first, this will often minimize anamolies you see when tuning left/right first. Also check for nock tension, too much will often cause odd results too. I also wouldn't make any final decisions until you've tested it over a couple of different days...some days a feller is just "off" from his normal shooting form and doesn't really realize it.


As Bob said, if the bow shoots good with the .400 setup you mentioned, the .500 setup the same would be weak...as long as the arrow diameters are the same. The larger diameter of the shaft, the more it moves the center point of the shaft away from the sight window, in essence stiffening the arrow slightly.

I agree with the advice already given, fiddle with some lower point weight and see what happens before you cut.

[Ragnarok Forge]

Just a thought.  Next time start with the full length arrows and the heads and inserts you want to use.  Then cut bare shaft to fletched tune and slowly cut them down until the arrows tune out right.

I am going to have to read Adcocks tuning page again.  I must be loosing my memory.  I thought fletched shafts left for right handed was stiff, and fletched shafts right was weak for some reason.  I haven't tuned in a while so I may just be remembering wrong.  Reading the tuning tips will clear it up.

[Dave Bulla]

Freefeet said "If you're right handed then fletch arrows impacting left of bareshafts is indicating weak shafts. "

Sorry Freefeet, but that is backwards.  For a right handed shooter, weak arrows hit to the right as the weak arrow bends more around the bow.  I used to get it mixed up all the time too...

[Old York]

Originally posted by Dave Bulla:
Freefeet said "If you're right handed then fletch arrows impacting left of bareshafts is indicating weak shafts. "

Sorry Freefeet, but that is backwards.  For a right handed shooter, weak arrows hit to the right as the weak arrow bends more around the bow.  I used to get it mixed up all the time too...

I believe O.L. says that fletched shafts  tend to go where they are pointed and thus one should use the fletched arrows as their reference...tune your kit so that the bare shafts end up landing in with the fletched arrows.

FreeFeet has it correct, his sin-tax     is just a bit different.

[beachbowhunter]

Originally posted by vermonster13:
Are you getting fletch contact with the riser?

It is possible, I've tried cock feather in and out. I used 3, 4" feathers and the 5" feathers on the CX arrows seem fine..  :confused:

[beachbowhunter]

Ok, a couple of details I left out. The point weights are the same (225 to 250), the fletching is smaller (4" vs 5"). Shaft diameters are very close to the same.  The fletched shafts are visually and apparently going left of my aim point. The bare shafts seem to impact closer to my aim point. I don't hear a click or see scratches suggesting a bounce off the riser. The bow is center cut (Gerlach 64" longbow, double carbon, 54@27). I think I might have to sacrifice a shaft and go shorter...

[JC]

If you shoot off the shelf, fletching will contact the riser no matter what pattern and how you rotate them.

As a right handed shooter, using same feather setup, same weight head, same length, when you shoot one fletched arrow of each (.390 and .500), the fletched .500 lands to the left of the fletched .390? If so, you definately have something interfereing or the spines are not calculated correctly. Or the .390 is bouncing off the shelf and giving you a false weak.

[Dave Bulla]

Before you go shorter, just tape a piece of leather to the side plate to add about 1/16 or a tad more thickness to it and try again.  You can go quite a bit thicker but I'd start thin and work up.

Old York, I've read O.L.'s page but it's been quite a while.  All I know is what I've found personally in my years of shooting and tuning my own bows.  For ME, as a right handed shooter, stiff arrows shoot to the left.  Weak arrows TEND to shoot to the right but as you get weak, they can do some weird things as they distort more in flight.  The general rule though is usually pretty true if you are anywhere remotely close to the correct spine.

[beachbowhunter]

Originally posted by JC:


As a right handed shooter, using same feather setup, same weight head, same length, when you shoot one fletched arrow of each (.390 and .500), the fletched .500 lands to the left of the fletched .390? If so, you definately have something interfereing or the spines are not calculated correctly. Or the .390 is bouncing off the shelf and giving you a false weak.

That is exactly what is happening, but I really don't think the .390s are bouncing. Their flight (several different shaft types) is actually quite good.

[JC]

Lighten point weight before you cut...and you've checked nock fit?

[JC]

Originally posted by Dave Bulla:
For ME, as a right handed shooter, stiff arrows shoot to the left.

Dave, that is correct....bareshafts will land to the left of the fletched shafts if they are too stiff (freefeet said that, just referenced differently). You have to differentiate between "arrows" and bareshafts and the planing method always looks at where the bareshafts land in relation to the fletched shafts, not vice versa. Unless something is interfereing with the flight of the arrow as it leaves the bow for a right handed shooter, the bareshaft landing to the right of the fletched shafts means weak...bareshafts landing to the left of the fletched shafts means stiff.

[Tom A]

Sounds like your arrows are too stiff. Bare shafts should show some weakness in order to get fletched shafts to hit dead on. If you are using really large feathers you are adding a bunch of weight to the back of the shaft making it stiffer.