Nock fit is an often overlooked aspect of proper bow tuning. Improper fit can can decrease your accuracy and even make firing your bow dangerous.
How tight should arrow nocks be? Arrow nocks should be secure on the string and not fall off. A “click” sound will let you know that the arrow is secure on the string. They also should not clamp the string, which will reduce the accuracy of the bow.
There are five simple checks that you can do to make sure that your nocks are fitting properly on the string. You don’t need to be an expert to do these checks.
Just for the sake of quickly understanding how nocks are supposed to work:
Notice that the inside of the nock is kind of like a teardrop shape. This allows the nock to click on to the string and not fall off.
The mouth of the nock is smaller than the string, so it captures the string in place.
The throat of the nock is very slightly larger than the string so that the arrow doesn’t bind at any point in the draw and release cycle. The throat of the nock should not be clamping on to the string.
Checking Nock Fit With the Tap Test
This is one of the simplest, tried-and true methods of testing nock fit.
To do this, just nock an arrow and allow it to suspend from the string. Then, about an inch or two from the arrow, give the string a sharp, firm tap.
The arrow should be able to hold its own weight on the string and drop when the string is tapped.
While it’s the simplest and most common check, this doesn’t actually give you the full picture of whether your nocks are properly fitted. Many nocks that are too loose will still be able to hold their weight on the string (although barely).
That’s why it’s good to do a couple more quick checks:
Nock Rotation
This is another easy check, and it’ll let you know if your nock is clamping on to the string too tight.
Nock an arrow and rotate it around the string. The string should stay straight as you rotate the arrow. If the nock is too tight, it’ll clamp on to the string and force it to twist along with the arrow.
So on my setup here, I’m wanting to see that my D-loop doesn’t turn around as I rotate the arrow around the string. If it twists the string, the nock is too tight.
Nock Wiggle
This is kind of like an extra check to the rotation. There should be a VERY SMALL amount of side-to-side wiggle between the inside of the nock and the string.
Here’s an example of a nock that’s way too loose on a string:
There’s a pretty visible gap between the string and the nock. Ideally, you want to barely be able to see this, if at all.
I’ll have to fix this setup so that the nock is tighter on the string. It takes only the lightest tap to pop it off the string. Since I use this bow setup for hunting, I’d like to err on the side of too tight to make sure that the arrow doesn’t accidentally slip off and cause a dry fire.
Since nock points on the string can pretty easily obscure your view of this gap, you can also twist the arrow back and forth and side to side to get a feel for this fit.
Here’s that same setup, and I’m twisting the arrow back and forth. You can see that the arrow can spin very loosely on the string:
If your nock is too loose, it should be pretty easy to feel this with your fingers. The amount of give should be pretty minimal.
Nock Point Spacing
This is another overlooked aspect of a bow tune-up. It’s especially important for more compact bows, like compound hunting bows.
If the spacing between the nock points is too tight, it will squish the arrow nock at full draw. If it’s too loose, your arrow won’t consistently sit at the correct height on the string.
On my setup here, it’s just a little tight:
This should be firm, but not tight. A very small amount of wiggle up and down the string is ideal.
Remember that at full draw, these nock points will tend to squish against the nock, making everything tighter.
Also, string-only nock points tend to be much more forgiving than one that uses a brass point, like what I have on my setup.
Sound
The last check that I do for nock fit is to just listen to it when I snap an arrow on.
You should be able to hear (and feel) a distinct clicking/snapping sound when the nock pops into place.
That popping sound is actually a good sanity check when you’re getting ready to launch an arrow. If it clicked, you know it’s properly in place, and you’re less likely to slip up and cause a dry fire.
Once you’re familiar with these simple checks, inspecting each arrow nock should take just a few seconds of wiggling and tapping. This can also alert you to some issues that may come up over time, like wear on your nocks or serving.
How to Fix a Loose Arrow Nock
Never try to bend your nocks!!!
Seriously, the accuracy and sensitivity of arrow nocks is something that is not worth messing with.
The best case scenario is that you have inconsistent nocks, which makes it difficult to properly dial in your shots.
Worst case scenario, you weaken your nocks and they break when you fire them.
The proper way to deal with this issue is to fix your serving.
You can redo your serving with thicker serving string. This is usually just a few bucks at a pro shop, and it’s also pretty easy to do it yourself.
If you just need to do some minor adjustments and only have one size of serving string, here’s a hack that can work:
Add a bit of serving string inside the string strands, then wrap the serving over. This can make the fit slightly tighter. This isn’t a good fix if your nocks are way too loose.
The proper way to do it, though, is to just use the proper serving string size.
How to Fix a Tight Arrow Nock
I’ve heard of some guys taking a needle file to their nocks to get them to loosen up a bit.
Don’t do this!
Again, all your arrows will be inconsistent. Also, the scratches that you put in the nock when you file it can cause stress risers that make the nock crack when it’s launched.
Modern bows are powerful, so the nocks need to be solid to handle this force.
The proper way to fix this is again to redo your center serving, but with a thinner string. Always modify your serving, never the nocks themselves.
If you need your nocks to fit just slightly looser, here’s a hack that occasionally works:
Redo the center serving with the same serving string, but put the string under extra tension and wrap the serving string as tightly as you can manage.
Most commonly, this will do nothing. But sometimes the tighter winding will help the nocks to fit a little less tight.