In this article, we take a look at the various airsoft nub spacers available in the market. The nub is a little tiny device that sits on the lever arm in the hop-up unit. When the hop-up is increased, the nub pushes down further on the bucking, increasing friction to make the BB spin. For each hop-up nub, we provide an objective description of the spacer first, then we provide our experience of it.
The rubber tube nub is basically a rubber tube cut into the length of a nub. Because it is made out of rubber, it is soft and squishy.
My experience with the rubber tube nub comes from the Echo1 Red Star IGOR VSS Vintorez, whuch comes with the Mad Bull bucking. The rubber tube nub does not seem very consistent at all. The VSS has a sliding version 3 hop-up unit. With the hop-up at the lowest setting, the gun seems to shoot straight to 100 feet. So that is where we sight the red dot sight to. We would put the gun on the shelf for a week or two. The BB would drop to the ground at 50 feet. We would slide the hop-up back and forth a few times. The we would set it to the lowest setting. All of a sudden, the gun would shoot straight again. we have never seen this kind of inconsistency with the plastic H-type nub (see below).
The fishbone nub is very similar to the H-type, described below. It is also hourglass-like, except the hourglass is sharp angular straight edges. Think of the fishbone nub as two martini glasses fused at the stem.
We have gotten the fishbone nub with the Mad Bull 60 degrees shark buckings. The fishbone nub is also made out of rubber, similar to the Mad Bull rubber tube nub mentioned earlier, which leads us to believe that all Mad Bull nubs are made out of rubber.
We have found that the fishbone nub fits just snugly in a version 2 hop-up unit (APS M4 URX Raptor), but it will not fit in the version 3 hop-up unit (Echo1 Red Star IGOR). Strangely, the shark bucking that comes with the fishbone nub is too thick for the APS hop-up unit, but it fits fine in the Echo1 hop-up unit.
The H-type is a cylindrical nub carved into an hourglass-like shape. The final result is a nub that looks cylindrical from the side, but looks like a 'H' from the front and back.
The plastic H-type hop-up nubs came with all of our APS M4 airsoft guns--APS Mini Patriot M4 and APS M4 URX Raptor. These guns shoot extremely precise with this nub. We only had to adjust the hop-up once and sight it in with the red dot sight. We never had to adjust it again. So far, we are a firm believer of the H-type nub.
The metal H-type nub is exactly the same as the plastic H-type in shape. Instead, the only difference is in the production material.
We have not tried a metal H-type nub before. But we cannot imagine how a metal H-type nub would perform differently from a plastic H-type nub.