One of the really small things that can be overlooked in archery. And I do mean literally small It’s the size of your nocks. Now for most people, this won’t really matter. But it does matter. As most of you know by now, when you nock the arrow it clips on to the string and the nocking points hold it in place. You draw the string back you let it go and the arrow comes off. What you may not know, is that arrow nocks actually come in different sizes. Having the wrong size can lead to significant spreads in your groupings. There are two aspects of nock size. The size of the throat and the size of the slit. Here, I have two different Easton pin nocks. The green one is large and the red one is small. Though bear in mind that these are just my colour choices and you can get these in any colour. For comparison, I have also got several other assorted arrows. There are a few simple tests you can do to check nock size. Nock your arrow and point the bow down. It should stay on by itself. If the arrow drops off completely, the nock is obviously too wide. Next, twist the string in your fingers. The arrow should stay in place. Finally, give the string a sharp tap. The arrow should fall off. If the arrow passes these tests you have got a good fit. Here, I am testing my smaller nocks on the same string. The arrow doesn’t rotate. So the throat is fine. But, tapping it, doesn’t achieve anything. So the slit, is too narrow. Here, I have got a much thicker centre serving. Using the small nock you can see that as I rotate the string the arrow also moves. If the throat is too small and thus the arrow rotates with the string the action of releasing the string off the fingers will induce a horizontal force. This will lead to left and right inconsistency. If the slit is too small then the arrow will have a harder time leaving the string. It will leave the string regardless. But, the tighter it is the more energy it takes, for it to leave the string. Which means it loses velocity. Not only that, if it has to fight it’s way off the string there are irregular forces acting on it. With a slightly larger nock it leaves the string cleanly. Which means there is less force acting on it and it’s going to be a cleaner, straighter shot. What this means, is that if you don’t have nocks that fit then, your groupings won’t be as tight as what you are aiming for. You can still shoot very well, but, this is one of those one percenters, which will come back to haunt you if you are trying to beat your personal best. In terms of exactly how snug the fit should be that doesn’t matter too much. For target shooters, having a slightly wider nock that can be easily be tapped off, means it is optimal for range. But, if you are a bow hunter and you are in the field that size might be too clumsy, because arrows can be knocked off. So you might want to use a tighter nock. But, if the nocks are way too wide and the arrow is falling off before you have even shot that is extremely dangerous. The arrow comes off the bow before you release it you have effectively dry fired it and that can destroy your limbs. It is worth noting that if you are are using factory made strings rather than making your own, the centre serving is usually on the slightly thicker side. So it is a tight fit for most nocks. If the centre serving is too thin and the arrow falls off too easily you will need to address this. You can use dental floss to add padding to the serving. But this is generally recommended as a short term temporary measure because the dental floss will over time wear out and you will have the same problem. The only way to properly address this, is to replace the centre serving or, replace the nock. You can take off the serving and use a thicker thread to make it thicker. Some people actually use a double layer of serving to make it extra thick. Or, you can work the nock itself. Some people would use a drill to widen the throat and slit. Generally speaking though, as long as the nock fits and the arrow doesn’t fall off, it’s fine. Getting that perfect fit isn’t as important for a beginner but if you are past that stage and looking to optimize your scores then, it starts making a difference. Anyway, I hope you have found this helpful. This is NUSensei, thanks for watching and I will see you next time.