Arrow Tuning Mystery. This is weird!

[J-KID]

Alright you tuning guru's - here you go.  This is really weird.

You got my 62" Tomahawk SS at 50# tuned for me with Carbon Express Heritage 150's cut to 29.5 with 200 grains up front.  Bare shafts fly right into my groups.

I recently acquired a 62" Tomahawk SS at 55#.  Both have the same string, brace height, nock point and silencers in the same location.

Bare shaft the 200 grain head in the 55# bow and it consistently hits extreme nock right which is supposed to indicate too stiff an arrow.  The other data supports this because if I shoot the 200 grains with feathers it is still nock right.  I have to move up to 250-300 grains up front to straighten it out.  The 250 grains up front seem to be shooting best bare shaft and with 3 or 4 fletch from the 55# bow.

What is going on here?  This tuning stuff is for the birds (but great when you finally figure it out).

[Don Batten]

Same shelf material? and thickness? DB

[J-KID]

Exactly the same shelf material.

[sendero25]

Hey Dr. Kidwell,
Another T-Hawk? Did you decide against the Widow?
My Desert Fox 64" 55# shoots 2018s with 250-300+ up front as well, it seems to like the heavier front end, with 3 5" shield cut feathers.
I shoot a shorter arrow so I am probably no help at all!
The only carbons I have are Grizzly Stik sitkas, and easton axis 500s I shoot from lighter bows so I don't know anything about the CE's. Are the 150s anywhere near the spine of a 2018?
Wish I could help and good luck!
John

[J-KID]

I'm still very interested in a Widow and an Arctic Fox.  I just want to try one first if possible.  I'll be patient and see what possibilities open up.  I got This T-Hawk like new and the extra weight and dirty boo limbs will be better for hunting.  I have no complaints about how they shoot.  My son-in-law and future son-in-law are showing some interest so the extra bow will come in handy.

Don't know how to compare the carbons to aluminum.  According to the spine chart, 55# is max for the Carbon Express 150's.

[O.L. Adcock]

1/64" difference in centershot makes a big difference in arrow spine. Plus, I don't know about those but many bow brands will vary 5-10% in performance between bows identical in everyway to each other to the eyeball. Consider every bow to be different, cause they are....O.L.

[ChuckC]

Are they really the poundage listed ?
ChuckC

[J-KID]

I agree about the subtle differences in similar bows.  I've noticed that many times over the past 25 years.  I stated the similarities to let you know they were as close to the same as I could get them.

The 55# definitely shoots an arrow faster.  The first 10 arrows I shot through it I put 2 clean through the bag target.  Never have done that with the 50# bow.

As a side note, I've noticed over the years that I can make about any arrow, within reasonable specs, shoot well out of my bows.  I somehow tend to adjust my form (I guess) to the arrows and I can do that now if necessary.

[Molson]

Have you tried a lighter point?  I've had them act like that when they were way too weak.

[J-KID]

No I have not.  I lightest I can go is 150 grains since I'm working off a 50 grain insert.  I'll try that tomorrow and see what happens with the bare shaft.  The nock right is quite extreme with 200 up front.  It does straighten out with 250-300 up front so that is probably not the problem unless I'm so far outside the lines I'm seeing stuff I shouldn't be seeing.

[J-KID]

I think I have a stupid question (as in, maybe this is what everyone does).  Right now my 50 grain inserts are epoxied in so can I just cut off the nock end a little at a time to shorten the bare shaft as I tune?  The nocks just push in.

I waiting on some full length 150's and 250's to tune with.  In the mean time . . .

Right now, at 20 yards, my fletched arrows are on the bullseye and the bare shafts are hitting about 10" to the right of the bullseye (with nock right which is the weird part).  I think, according to the Adcock instructions on tuning, that is probably telling me the spine is a too weak.  If I shorten the bare shaft 1/8" at a time I can see if the bare shaft will move over to the bullseye to confirm the weak shaft.

[Smallwood]

yes, you might try cutting it 1/2" at a time, just remember to cut both the fletched and bare shafts. In theory, if they are too weak, and you shorten them, the point of impact should move to the left.
o.l. could probably explain it better.

[Kingwouldbe]

Hi Jay, if the bare shafts are hitting to the right of your fletched shaft, there week, nock direction does not matter, just where it hits.

I try and get a group about 2-3" to the right and about the same low, when fletched they shoot like darts.

[katman]

Make sure you are not torquing the bow on release with the heavier poundage.

[J-KID]

I did some cutting and I'm glad to say that my bare shafts and my fletched arrows are tight in the bullseye at 15 yards.  Thanks for all the help on this.  I was paying too much attention to nock direction and not arrow location.  I was mixing methods I guess.

Bottom line: I think tuning arrows is as much an art as a science.  Thanks all you artists.

[O.L. Adcock]

J-kid, "Right now, at 20 yards, my fletched arrows are on the bullseye and the bare shafts are hitting about 10" to the right of the bullseye"

2 things will cause that, one is the arrows are weak...The other is they are too way too stiff. NEVER EVER cut shafts until you verify with point weight..Go down in weight until they shoot good and cross over to stiff. At that step you can go up to the point weight you want to shoot and cut until they dial in. If you go down in point weight and they continue to group right, they are too stiff and you need more point weight....O.L.

[J-KID]

That is what was confusing me in the beginning.  I thought they were showing weak spine but in reality they were too stiff.  I got it figured out after some comments to that effect.  I tried lots of point weights and ruined two arrows but it was worth it.  I'm shooting 200 grains up front and the groups are good. Total arrow weight is 580 grains.  I'm going to stick with your arrow planing method from now on.  I'll test broadheads against field points this week and see what happens.