Board Thread:General Nerf discussion/@comment-27985798-20200503233516/@comment-27306930-20200508041011

I just want to take a moment and talk about O-rings. The reason the "tape trick" works is because plunger tubes are not cylindrical. They're actually cones. Technically they're conical frustums.

In a stock blaster the tube is wider at the open end and the o-ring is typically sized to make contact with the inner walls of the plunger tube about a 3rd to half the way down the tube. Because of that, much of the air can escape around the plunger head.

By putting a little tape in the o-ring slot, it increases the diameter of the ring so it engages the plunger tube even sooner, effectively pushing more air through the breech and barrel.

But stock springers are all basically Jolts. (Sorry to burst your bubble)  The barrel is only as long as the darts. And once the dart leaves the barrel, the air isn't pushing it anymore. In fact, additional air exiting behind the dart after it leaves the barrel is counterproductive and leads to tail induced turbulence. Typically, it's only the air in the bottom half of the plunger tube that's pushing the dart out of the barrel. So increasing the diameter of the o-ring to push more air doesn't have any effect on the performance of the dart, and in certain cases can actually lead to decreased consistency.

The only benefit of pushing more air through the barrel is if the barrel is longer. And not those longer faux barrels, but actual sealed brass or PVC barrels. The additional air pushes the dart down the entire length. But if there's no Air Restrictor, much of this discussion is moot anyway. Like fluids, air moves through the path of least resistance. So if there's a choice between the open end of the plunger tube and a tiny gap between the o-ring and the wall of the plunger tube, the air is going out through the barrel.

Admittedly there's some loss. Let's say the total area of the gap in the o-ring is 2% of the surface area of the cross-section of the barrel. And I'm being generous. And let's say you expand the o-ring to completely fill that gap. In a stock blaster that's the difference between 70 FPS and 71 FPS. It's statistically insignificant.

I'm not saying don't do it, but focusing on the o-ring is about as effective as focusing on the color of the blaster. Spend your time and money wisely. Upgrade the spring, and get good darts. Then talk about AR removal and brass barrels.