Quote History LWRC used to have an ACB 5.56 but I've heard mixed tales on it working vs not working. Also read at least one statement that Paul Leitner-Wise still has/owns the patent to it and that's why LWRC no longer sells it. No clue on if it's true or not.
Have more pics of your rifle you don't mind sharing? Some information seems to suggest the M6A2-S was a "limited" rifle but can't find hard information on it. The other pics I saw appeared to have a standard charging handle.
M6A2 series didn't have as many bells and whistles as the later IC models with full ambidextrous setups.
Pull your upper handguard piece and take a look at your spring cup. If it's a polymer oval piece, you have their old setup. If it's a metal circle that connects to the upper receiver, that's their current design.