CC 6.5mm bullets vs 4mm bullets
 

Will i see any noticeable gains by replacing the 4mm bullets that came on my teckno Neu to 6.5mm CC ones? I figured that since the 4mm ones came on the motor they should be enough but if it is advantageous to use the larger ones then i will most likely switch them out eventually.

It won't kill anything to run them, but if you find they heat up during a run you should replace them with 6.5mm bullets.