tracer
 

ive bought a tracer unit and i want to know if the inner barrel can enter inside it a little or do not have to enter it because got 1 inside the tracer unit ? the tracer unit is one that screw on the ccw threading

You can put an inner barrel as far into the tracer unit as you want.
I assume your question is, will the tracer still actually work. Well if you take off the cover or look down the tracer when it's on you will probably see a faint red light from the sensor. If you go past that, it won't work.

thanks you