So i've decided to take the jump into NFA land and go get a suppressor. My trust is all set, just need to make up my dang mind already. Got it narrowed down between an AAC M4-2000 and a 7 SDN-6. I own several 5.56 AR's, however I do not own a 30 caliber gun as of yet, nor do I have plans to in the immediate future(bolt gun maybe?) Can you advise me on how much i'd be loosing performance wise going with the SDN-6 over the M42K? I suppose it'd be nice to have the ability down the road to shoot .308, but right now i'm feeling like i'd rather have a can that suppresses one caliber very well rather than several just OK. I guess there is the size/weight (one inch and an ounce or two difference) as well. This isn't the only suppressor I'll ever buy, just looking for someone to give me a good shove in the right direction. Feel like either way I'm gonna wake up with buyer's remorse on this one. 1st world problems for sure. Good news is I get full visitation rights from the dealer I'm buying it from which means I get to shoot whatever can I choose at their range as I please till the tax stamp comes in.