But here it goes:

I have an older KAC free float RAS that is about 7 inches long.

I am looking to get a barrel in 300 Blackout with a Breakout comp and an ACC 762-SDN-6.

What would be the shortest barrel I could go with, without interfering with the quick disconnect or the silencer in general?  

Basically I am asking if I can get away with the Noveske 8 inch barrel or am I going to have to use the CMMG 8.5 inch.

I know that the silencer will not fit under the hand guards,  but I wouldn't want them to anyways.

Thanks ahead of time.

And I will try and take a picture of the set up.

You could get a 10 inch barrel, and have it cut to get that hella flush look.

http://i15.photobucket.com/albums/a369/RedFireCobra/AR%2015/IMG_0126.jpg

http://i15.photobucket.com/albums/a369/RedFireCobra/AR%2015/IMG_0125.jpg

http://i15.photobucket.com/albums/a369/RedFireCobra/AR%2015/IMG_0127.jpg