I looked at the pin further and compared to the LMT pins I have and noticed the length of the sides on the KAC are the same and the LMT are slightly different, which would facilitate easier insertion. Not sure if this is an issue or not.
The design is not like a standard cotter pin, as these are designed to bend for locking, but a cotter has un equal lengths for ease of insertion and for grabbing the longer length to bend and lock.
I will be taking the BCG apart after another two or three range trips to inspect and clean, will update then.
I am getting ready to place another LMT order and will add four or five FPLPs to the list.