My brother has always wanted a primary to use, but he just can't prime a K26 to full compression. Even if I were to make a snap with a shorter K26, he would still have trouble with it. That is why I decided to make a rainbow. With a rainbow, I can put the catch notch anywhere that I want so I can use a K26 without making it have full (or near) compression.
Rainbows are kind of like Snapbows except they are a little longer and use a rainbow catch. I used a rubber washer as a plunger head instead of a skirt seal because skirt seals are so expensive. The washer is working pretty well but I still need to work on the seal because it isn't very good. The main challenge of this blaster was using opaque PVC instead of clear. Clear PVC is very expensive and I didn't want to buy more of it for a basic rainbow. In the writeup for the rainbow, it tells you to use clear PVC because drilling into polycarbonate through opaque PVC is a bad idea. I kind of agree with the write up but I eventually got a method to drilling into the catch. You can look at the picture below and see the holes I made by missing the catch.
The holes aren't really a big deal because the rest of the blaster is pretty clean. It only features about 5-5.5" of draw on it because I wanted my brother to be able to prime it. I don't have measured ranges but it doesn't get far off my Snapbow's ranges with a hopper. It is really easy and comfortable to pull back with the polycarbonate pull. It is even easier to pull back than my Rainbow pistol. The blaster also includes a very nicely sanded handle for extra comfort. Overall, this is a very nice blaster.