How to upgrade gel blaster plastic inner barrel to metallic inner barrel to improve speed and accuracy

The inner barrel of a gel gun is around 27 -35cm. If your gel blaster comes with an acrylic plastic inner barrel, you can upgrade it with an aluminum barrel, a longer metallic barrel can reduce the vibration (or shaking) of the barrel and keep the gel ball travels with a steady direction inside the barrel, which improves the speed and accuracy of the gel blaster. Warm reminder: If you use a longer inner barrel, you need to use a higher % cylinder.

Alternatively, you can keep using the acrylic transparent barrel and mount some tape on it, this can also lower the vibration of the barrel when the gel ball travels inside it.

Some gel blaster manufacturers make a trick on the inner barrel so that the gel gun does not shoots over 350 FPS out of the box. As the air leaks out of the inner barrel, less energy for pushing the gel balls along the barrel, hence the gel balls travel with a much lower initial speed.
 
If you find a small hole in your gel blaster (especially SLR), you can either replace the barrel with a new one or simply invert the barrel, so that the small hole is at the end of the barrel, this can already minimize the impact.