I have been working on this for quite awhile, It is finally done, all that needs to be done is workout some loads for subsonic.
I have wanted to build a M16 with the look of an MP5SD and when I came across the 300 whisper It actually made it possible. Originally I was going to just make one in 5.56, however the 300 whisper is the perfect round for this.
About the rifle..
Colt M16A1 receiver, although I may go the SBR route shortly.
Bushmaster upper receiver
Gemtech TPR-S suppressor with bi-lock
Del-ton 300 fireball barrel that started at a 16" preban and was cut and threaded to 9" for the bi-lock
YHM rifle length free float quad rail
Aimpoint CompM with ARMS mount
Troy front folding sight and a GG&G folding rear sight
Ammo made from .223 Winchester brass sized with redding dies and loaded with 220 HPBTs
Using a trial loading of 10.0 grs of H110 and the 220 HPBTs the rifle cycles fine, just need to get ahold of a chronograph to get a final load.
Threaded Mode