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Discussion Starter · #1 ·
Bare shaft tuning (again). I got some carbon arrows (to replace my aluminum ones), and I have been practicing at 15 yards. These arrows are about 40 grains lighter than the aluminum ones, and at 10 yards the bare shaft was grouping decently (still angled nock right). Not so much at 15. I was aiming right on the target to make sure the bare shaft would not miss left. This is a view from the TOP.

I am right handed. My rest is set just under 1/16" out, measured all the way at the tip of the arrow. Adjusting the rest had no real effect on the bare shaft, I moved it 3 turns each way, no major changes.

The arrows are 29" long. My bow is 40# at 28", my draw is about 27.5".

I'd guess that this is heavy spine/too light of a tip again, but according to the chart at 150 grains it wants me to go up to the next heavier spine.

Arrow with 100 grain tip:


Arrow with 170 grain tip:


Arrow with 275 grain tip:


I just put on a new string, made from BCY X, it is MUCH faster. The angle of the bare shaft got worse.

Is this a spine issue, or something else? If it is a spine issue, I have been debating on going to heavier limbs before dear season, should I go with 45's or 50's?

Thanks
 

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It looks like it's flying nock right regardless of tip weight. Since tip weight affects "dynamic spine" and the angle isn't changing, I think I'd look elsewhere. Not sure where though. Maybe play with centershot or plunger stiffness? My wife's arrows do the same thing and I haven't figured them out either, so alternate suggestions are welcomed.
 

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Personally I'd bring the plunger in until you have just a small left offset and increase the BH.
In my experience BS angle is usually related to centershot and clearance.

-Grant
 

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Centershot doesn't seem to do much, but going with a heavier tip gets the arrow more on target. With the 100 grain tips, it hits INCHES left.
It looks like it's closest with the 275 gr tip which makes me think the spine is indeed heavy, in addition to whatever other factors which may be in play.

You never really told us the spine rating of these new arrows.
 

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7" sounds extremely low in BH for most recurves.

What bow are we talking about here? Also need to know more about the arrows.

-Grant
 

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All due respect to target shooters out there it’s a common misconception the centershot changes spine. As you (and I) found out it does not. It affects impact relative to fletched arrows, which you would tweak once you have the right spine. Your bare shaft is “stiff” which is a bad term IMO. The arrow needs to slow down to fly straight as this has to do with the timing of the string/nock separation, you do that by adding weight to the arrow or string. The only way to change the arrow vibration frequency is to add/subtract weight or make the arrow longer (which also affects speed). The amount of bend in it does not change the frequency, which is why centershot doesn’t work.

But the first thing you always want to do is make sure you don’t have any arrow rest/shelf contact. It cost me $80 last year to figure this one out. If you put masking tape running the length of the arrow you can see if there is any contact, and where. It also works on the shelf, as contact on the outside is common which bounces the nock left making the arrow appear weaker (until you cut too much off and realize it was actually too stiff!). Nock height can help if you have some shelf contact. Or a grinder as I have done. Once you do that finding the right spine is as easy as arrow length and/or tip weight. You should be able to see the nock move back to the left by adding weight, and vice versa. That’s why I have tips from 75-175 grn (or no tip which is 0 grn).
 

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The arrows are 500 spine, same as the old ones (which did the same thing).

7" is correct, its a Martin Panther take down.
"same thing"???
Now I think we're on to something. It's a bit unreasonable to believe you can use the same stiffness and expect different results.

The images look like it's fairly strongly reflexed riser, making it a bit squirrely to shoot and with the low brace height, it may need different arrows than the standard recurve charts.

Although you would think one would need a stiffer arrow with this bow, if you can find some weaker spine arrows (.600, .700, just for testing) and try those then we can eliminate spine as a possible issue.
 

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Discussion Starter · #12 ·
I didn't expect it to change, I didn't even know it was wrong. I didn't bare shaft either until I got the carbon arrows.

Even finding 500's in stock is hard to do, I doubt I'll ever find a 600 what wouldn't involve me ordering 6 or 12.
 

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Just a few thoughts for you.

First off, move back. Fifteen yards is fine to start with, but at that close distance you are really only making sure your bare shaft will stay on the target. Once you are sure of that move back to at least twenty yards. Once you get tuned in there, move back to twenty five, then thirty. What looks relatively decent at fifteen yards might be not nearly so decent as you move back.

I would also do your bare shaft tuning with more than one bare shaft. More than once I've had a bare shaft that didn't fly the same as other bare shafts, usually some imbalance in the nock that was corrected by turning the nock or replacing it. The point is I wouldn't have known there was a problem with the shaft if I wasn't also comparing it to other bare shafts. I like three bare and three fletched when I'm doing serious tuning.

I also like to shoot all arrows every time. Looking at your photos it looks like the fletched arrows are the same group and the bare is shot separately with different weight points. Either that or you are very consistent with your fletched shafts. When you change point weight, change it on all the arrows and shoot them as an end. If I'm incorrect on the assumption I made by looking at your photos, my apology.

My guess is like the others, your shafts are too stiff. I would try to create a weak condition. Like they say you don't know if you've gone far enough until you've gone too far. When you find the right spine, shaft length, and point weight, you should be able to make your arrows stiff or weak with a small change in one variable.

I'm going to assume you don't want to go heavier than the 275 grain tip you've tried so all you can do is try a longer .500 or a weaker spine. Sometimes it saves time to make a big change instead of sneaking up on things. I'd consider buying half a dozen full length (uncut) .500s, preferably fletched with feathers to eliminate one more variable. Length makes a big difference with carbons and I'd guess the difference between your 29" arrows and full length might be significant. Especially if full length is a full 32". Either that or half a dozen .600s. You need to find a weak arrow, then you have at least bookended the problem and can work in between.

Usually feathers are more forgiving than vanes if you are getting contact issues. That wouldn't affect your bare shafts but you might be getting some contact with your fletched arrows and that might have a negative influence on your tuning. Hard to say over the internet. Lots of people shoot vanes of an elevated rest but in general feathers will be more forgiving.
 
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