1. Gemtech muzzle brake with removable Gemtech Blast Diverter
2. Fer Franz (sp?) muzzle brake with Fer Franz removable blast diverter...
both of which require an inch or two of barrel access between their muzzle brake and the hand rail. These are nice because you have the option of removing the added weight of the diverter, but the length stays about the same because those muzzle brakes and diverters (both the Gemtech and Fer Franz) terminate on the same plane, or about flush. I have a brand new Fer Franz I need to pass along since my freefloat rail covers about two inches of my muzzle device. My Fer Franz diverter's attachment knob can't be accessed while trying to lock/unlock the diverter onto my muzzle device (I figured this out the hard way! lol). I ended up getting a KX3 while waiting for NFA to parole my new suppressor.
3. KX3 or KX5
4. Suppressor (like the Saker, has no attachment/release knob, it'll screw down inside of a freefloat rail that's at least 1.5" diameter (+/-), and good down to 7" barrels for 556.
eta I fired the first round thru my 7.5" ar/pistol, aka future Saker556 platform, with only a Saker muzzle brake, inside a small room, only once! It ROCKED my world lol! Bought a KX3 so I can stretch its legs a bit while waiting for my suppressor.