EFOC bareshaft flies nock low

[Michael Henschel]

#130849

Dear Tradbow community,

I’m from Germany and I’ve registered for this forum because I’m trying to understand a strange bare shaft flight behaviour that I’m seeing with my 650gn arrows that have a 20% FOC.

I’ve also posted this in the Tradgang forum but searching the web I found “Friends of FOC” forum, which might be a good place to find an explanation.

Let me describe the issue. First off, I believe I’m able to tune a bare shaft and find out the right nock height for the setup.
I have successfully done so with my 55# (@30″ draw) hybrid longbow. With this bow I tuned a 400 spine GoldTip Traditional arrow with 30″, 100gn tip, 40 gn insert. The bare shaft flies perfectly straight and hits the same spot as the fletched arrow.

I’m now trying to set up the nock height for my recurve bow, which has 60# (@30″ draw) and which shoots a 340 spine GoldTip Traditional arrow with 30″, 175gn tip, 100 gn insert (results total 650gn with 20% FOC). I’m shooting 3 under. The bare shaft flies perfectly straight in regard to left and right. So I assume that I have found the optimum dynamic spine.
However, the bare shaft flies nock low considerably. It’s perfectly visible during the flight. However the shaft is hitting at the right spot.
I have started with nock height of 4/16 (lower edge of the nock)and went up to 10/16, which is awfully high. Only then was the bare shaft flying more or less with nock horizontally. But I never saw it fly nock high!
With this setup I then tried shooting a 400 spine bare shaft, which was more or less set up with the right dynamic spine for this bow. Now, this bare shaft was flying with extreme nock high! (As I would actually have expected all along, since 10/16 nock height should really be way too high). It was actually unshootable.

I’m puzzled now and I’m asking myself if an EFOC bare shaft behaves different than “normal” FOC arrows .

Has anyone experienced something like this before?

Best regards Michael

[Robin Conrads]

#130898

Hello Michael,

Welcome to the site. Although we aren’t as big as the other forums on the Internet, this is a friendly and helpful group. I’m sure someone will come along soon with some suggestions.

Robin (aka Webmother)

[Michael Henschel]

#130942

I also posted this reply in theoriginal Tradgang thread:

I think I resolved the problem. But I’m still failing to understand it.
I lowered the nock height back down to 4/16 (lower edge of the nock) and now the bare shaft flies pretty good. I find 4/16 rather low but this solved the problem in this case.
But I just don’t understand why these arrows behave this way. If I go up with nock height just a little bit the bare shafts start to fly with nock low.

Does someone have an idea?

Michael

[Raymond Coffman]

#130981

Michael

I was hoping the Doc or Stephen Graf might chime in as they know a lot more about this than I do. I have gotten good flight setting up efoc arrows in the same weight range as yourself.. without the extreme Nock pos issue.

In other discussions on the forum in the past — 2 things come to mind reading your description of the problem.

Is the second bow ( recurve) designed for shooting off the shelf ?  – sometimes this needs to be doctored to get good flight

Shooting 3 under with some bows can also cause issues – I shoot Mediterranean so can’t speak with experience about this. I have even heard of bows specifically built to shoot 3 under —-

Welcome to the forum even if we Havn’t been too helpful –

What part of Germany do you live in? Can you hunt in Germany with your bow?

Scout aka Ray Coffman

 

 

[Michael Henschel]

#130984

Hi Scout,

Is the second bow ( recurve) designed for shooting off the shelf ?

Yes it is. It is a Bearpaw Hawk, which is a Black Widow derivative.

What part of Germany do you live in? Can you hunt in Germany with your bow?

I live in the Frankfurt area. Bow hunting is not allowed in Germany unfortunately.

 

 

[Raymond Coffman]

#130988

Michael

Ah yes – a bodnik bow ( read their book) visited the site, looks like a nice stable shooting bow. You might try shooting med style – see what happens.

I know for me- sometimes I get pretty tired and/or frustrated trying to get a new arrow set up tuned, i’ll start making mistakes in form, throwing my test out of whack. If that happens I take a day off.  When I go back, the arrow seems to be flying better than I thought- haha —

Had the pleasure of visiting Germany and Frankfurt a couple times, enjoyed it thoroughly –unfortunately a long time ago, last time in the late 80s.

Do you have to shoot on a range ? Or can you shoot at your home?

Scout

 

 

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