Arrow Runout: Axis vs. Aftermath

[SJP51]

Easton made a 6mm Axis arrow that I still shoot. It has a spec of 0.003" runout. Getting hard to find and expensive at $120/dz.

Easton still makes a 6mm shaft called Aftermath. It has a spec of 0.005" runout. And only $60 dz.

I like the 6mm carbons and want to stay with them.

Will a .005" runout arrow fly noticeably worse than the .003" arrow?

[SharpEnd]

It depends. If you are building your own arrows you can use an arrow spinner to see which end of the arrow has more runout, and cut that end. It might turn the .005 into a .003. Of course the same thing applies to the .003 arrow. It also depends on how short you are cutting your arrows. If you're taking 3-5" off of the bare shaft length you can cut one or both ends to help reduce the runout. At 20-30 yards you probably won't notice a difference anyway, but if you're taking longer shots, particularly with a broadhead, you may see a difference in consistency.

[Buffalo1]

If you shoot enough you will see the difference in the dispersion of the .005 vs the .003.

That being said, if your .005 is full length, 2" can be trimmed off the butt and then cut to desired length with the overage on the front of the shaft. End result shaft straightness will a little more than .002.

[RifleBowPistol]

I am going to say probably not, .002" run out difference, is a very small amount. Bows are not that precision. I would like to know, how are they measuring the runout. Is that .005" runout, with a arrow in something like a lathe and then spinning it and getting .005" runout, or are they saying .005" from being perfectly round at any given point on a shaft?

[SJP51]

The spec is talking about "Total Indicated Runout" or TIR. TIR just means it's bent a little bit. Not whether the shaft has a circular vs. oval shaped cross-section.

Think of it this way. If you lay the PERFECT shaft (TIR = 0.000") on a PERFECTLY flat surface and roll it, it would roll smoothly with the shaft touching the flat surface over it's entire length at all times when rolled 360 degrees. No wobble at all.

Whereas, a shaft with a 0.125" (1/8") TIR would have visible bend in it, and hump and bump as you tried to rolled it. A shaft with a 0.005" TIR likewise not roll perfectly, but just maybe barely noticeable bend to the naked eye.

A shaft with "too much" TIR would wobble in flight. So the question is: Is 0.005" TIR too much? Would it be noticeable compared to a 0.003" TIR?

You can buy shafts with 0.001" TIR. They are more expensive for a reason. Seems to me like 0.005" is getting to be a lot of runout (wobble). But I'm not sure.

[SharpEnd]

I would like to know, how are they measuring the runout. Is that .005" runout, with a arrow in something like a lathe and then spinning it and getting .005" runout, or are they saying .005" from being perfectly round at any given point on a shaft?

There isn't a consistent standard between arrow brands as to how they determine their runout spec, from what I recall, and some (most?) don't reveal how they measure it. Easton has published their method, assuming it hasn't changed in a while, it was measured using the entire shaft minus 2 inches. Others might not use the entire shaft, but a 28" section.

[elkaholic9292]

A human hair is .004-.006 if that helps. I am of the opinion that the paradox induced into the arrow will more than make up this difference. If your budget conscious I say give em a try.