NOTES FROM LUKE: The Rival Artemis Spring is a custom made spring from a K26 that offers about a 120FPS average compared to the stock average of 95FPS. This mod is a bit challenging but it's definitely worth the effort.
Medium to difficult mod. You'll need to take apart most of the blaster but can leave the back plates on. On the internals, we found it’s a shorter and easier mod if you leave everything together and just take the front plate off the magazine chamber and access the plunger tube and spring that way. There’s a little screw that attaches the plunger to the lock mechanism that you can take out by slightly compressing the spring and accessing it that way. The custom K26 is a bit longer than the stock spring so after installing it, you’ll need to do some extra compression in order to get the three anchors back on from the plunger to lock mechanism and put the screw back in.
Check out our custom 3D printed parts for the Artemis blaster: