Recently, SureFire came out with a new adaptor specifically for AR's that have either a FSB close to the end of the barrel (like the 10.5 HK 416) or a rail. It is called the MB556K-SB and works with the 212, Mini and Micro cans from SF.
C4
http://www.gandrtactical.com/images/.../MB556K-SB.jpg

