Arrow flight question

[Gumbo]

Techies please give me some feedback. So I am having an issue with arrow flight. It seems my arrows are slighlty corkscrewing, which is more evident on longer shots. Here are the facts:

-Nitrum 34 @ 70 pounds
-27.5 draw
-Axis 340s cut at 26.5 (shaft only)
-brass HITs broken off at 50 gr, 100 gr field point (about 435gr total arrow weight)
-Bullet holes through paper at 6-8 feet
-no fletch contact (Hamskea hybrid)
-cam timing and lean are good (top about 1/12 inch early)
-arrow at 90 degrees through top half of berger
-3 fletch with V-max 2.5 inch vanes, 3 degree right helical
-nock tuned through paper @ 6-8 feet, all but a couple arrows flying perfect and those seemed improved by turning nock

I've never shot helical before, is some corkscrewing to be expected? Are the vanes too small (I just refletched 5 arrows with 3-inch v-max vanes to try)? Is it a spine issue, should I shoot 300s? Is it a form issue? Could it be wind?

Thanks in advance....

 

[mmccolloch]

Hey Gumbo,

I ran your setup through TAP (The Archery Program) and it looks like your a little bit underspined. See the attached picture for reference.



I just recently went through something similar to this with my bow (Bear Traxx at 70 lbs, 28.5" draw) and very similar arrow setup (Goldtip hunter 300, cut to 28", with 50 grain fact weight & 100 grain field point. Overall arrow weight of 460 grains)

I ended up doing a bunch of arrow testing with both 340's and 300's. I bought a couple of each spine arrow and had them cut to different lengths and pretty much just tuned my arrows to my bow. I got to the point where I could shoot bare shafts and fletched arrows in each spine through paper at 9' with no issues. I did notice that when I shot the 340's at longer ranges, they looked like they were corkscrewing through the air way more than the 300's. I also noticed that the 300's grouped better at longer ranges, so I ended up picking the 300's.

I'm no expert by any means, but I do know this seemed to work for me as now I'm running a 4 degree right helical with the AAE 26 vanes and can get my fixed blade broadheads to hit with field points out to 75 yards.

From now on, I'm going to approach arrows completely differently. Buy a few and try to tune the arrows to each individual bow.

Let me know if you have any other questions, I'd be more than happy to help out any way I can.

 

[jmez]

Most likely an illusion if you are seeing it with the bare eye. The fletching, esp if not all the same color will look like the arrow is corkscrewing.

 

[Jason Snyder]

Most likely an illusion if you are seeing it with the bare eye. The fletching, esp if not all the same color will look like the arrow is corkscrewing.

This was my first thought also.

I shoot AAE Max Hunters with no corkscrewing issues. It could be form. How do your broadheads fly?

 

[mmccolloch]

Jmez,

That is a very good point. I never thought of that. Although with my testing between my 300 spine & 340 spine arrows, it is definitely more apparent with the 340's. Both arrows have the same fletching configuration & color as well.

 

[mmccolloch]

I just noticed that the picture I attached in my first post did't work. I have reattached the picture.

 

[MT_Bow_Hunter]

I tend to agree with mmccolloch, that it's a spine issue. I used old arrows on a new bow and they had the same corkscrew effect. I switched to a 125 gr. head and that helped a little, then I got some stiffer arrows and the difference was like night and day.

 

[Gumbo]

Hey Gumbo,

I ran your setup through TAP (The Archery Program) and it looks like your a little bit underspined. See the attached picture for reference.

View attachment 35035


I just recently went through something similar to this with my bow (Bear Traxx at 70 lbs, 28.5" draw) and very similar arrow setup (Goldtip hunter 300, cut to 28", with 50 grain fact weight & 100 grain field point. Overall arrow weight of 460 grains)

I ended up doing a bunch of arrow testing with both 340's and 300's. I bought a couple of each spine arrow and had them cut to different lengths and pretty much just tuned my arrows to my bow. I got to the point where I could shoot bare shafts and fletched arrows in each spine through paper at 9' with no issues. I did notice that when I shot the 340's at longer ranges, they looked like they were corkscrewing through the air way more than the 300's. I also noticed that the 300's grouped better at longer ranges, so I ended up picking the 300's.

I'm no expert by any means, but I do know this seemed to work for me as now I'm running a 4 degree right helical with the AAE 26 vanes and can get my fixed blade broadheads to hit with field points out to 75 yards.

From now on, I'm going to approach arrows completely differently. Buy a few and try to tune the arrows to each individual bow.

Let me know if you have any other questions, I'd be more than happy to help out any way I can.

Thanks! It is help like this that makes me appreciate this site.

 

[Gumbo]

Thanks all, form and illusion are definitely considerations and likely culprits. I will be the first to admit I am not a spectacular archer, and torque and consistency are definitely issues I struggle with. As for illusion, it very well could be, but if so it is pretty damn convincing. I think I will buy a couple 300s and see what happens...

 

[mmccolloch]

Keep us updated on what you find! Good Luck!

 

[Jeff Martin]

Most likely an illusion if you are seeing it with the bare eye. The fletching, esp if not all the same color will look like the arrow is corkscrewing.

Bingo !!!!!!