Just SBR, once it's a SBR you can put anything on it like the front combo mag/grip. If it just had that and no stock it would be an AOW I believe. That's only $5.00 to the gov the last I checked. SBR is $200.00
Factory Glock longslide barrel cut and threaded.
On the AR15 if you have heard a suppressed one then this does not apply, If you have not a 22 and a Good 9mm can gets down to pellet gun quiet. Hollywood Quiet. I have a Gemtech for my M16, since it goes faster than the speed of sound the bullet created a ballistic crack downrange, (think airplane and sonic boom) since its downrange you cant do anything about it other than us Subsonic ammo but that slows the bullet down so much it will drop like a rock at 100 yards and since speed is everything for a 223 subsonic in my book is semi pointless.
223 cans at best with standard ammo sound like a standard 22. It does shut them up quite a bit but still it sounds like a 22
9mm (quality can) and most 22 cans are pellet gun quiet, they dont sound like a gun at all.
If it was my first can I would go with a 22 or at most a 9mm, those are a hoot, mostly just the action slapping around and a bit of a whoosh air sound. You could always get a 9mm upper for your AR and use the can on any 9mm pistol or rifle if you get the right one.
Rockets Out