I haven't had much success with it. I have the standard green and red pins and because the LED doesn't reach the ends, it doesn't add enough light to be usable in all but the darkest conditions.

If I were in your shoes with blue pins, I'd run the fibers through a tiny straw, like a coffee straw and them wrap that straw with electrical tape until it fills the sight tube. This is what I plan to try. I just haven't got around to it.

 

I'm doing pretty much the same thing with a 5 pin accustat that above post suggests. Keep in mind you only use enough fiber to go from the pin to the light. Try to keep the cut ends close to the same length and wrap with the tape to keep them in a tight bundle. I've been using this set up for 3D for quite awhile with no problems. * you will need the light on to see your blue pins

 

A friend of mine just did his accustat 3-pin with blue fibers. What he did was put his three fibers in a clear tube and ran it through the small hole at end of the barrel. You have to take it apart and you will see a small hole that is center of barrel. He ran fibers in clear tube, ran tube out end of barrel and took an earplug that you can roll up and then it reforms its shape. But he put tube through center of earplug and then cut tube and pushed it all back in barrel. Earplug swells back up and holds tube with fibers perfectly centered. Works perfectly