@dotty I had no trouble mounting a variety of hand guards on to the KJW. I installed a m16 length front end and with the triangular cap for the hand guards, m16a2 and m16a1 hand guards fit perfectly as well as the heat shield for my m203.
@ t_hum The upgrades are preforming magnificently, the only concern I have is that with the velocity reducer and a tightbore it's shooting 365 with a .25 which is over the limit so I have to experiment with one of the spacers to get it perfect.
For any who saw the picture Bleumaglite posted, I'm trying to convert a KJW m4 into a GBBR M16A1. I install