Originally Posted by BKHKMP5
Hmmm, I don't really get what you mean. The part that unscrews itself is the center section which is used to swap from the M4 length to the CQB length barrel. Please help me understand.
BTW, do you have the same problems as I do with the hopup not budging and the rear body pin being really tight?
The takedown pin may be tight because it's bent, or the holes in the receivers (could be in the upper or lower) are a tad undersized or filled with the finish material.
I've had to ream them out a bit before, even with a real AR upper.