Maybe its the light thing. Did you check to see if the bore for the light thing is bigger than the barrel?
that looked cool, but is the paint suposed to glow in the dark, or is it just the shells?
The paint glows, the shell is clear. The light thing only charges it for a split second so its doesn't glow for to long. Thats why it looks like a tracer. If you put it under a light it will glow longer.