The 5.56 Gail ACE Gen 2 utilizes a 1/2x28 thread pitch. Any of the 5.56 VG6 Precision AR-15 Epsilon Muzzle Device's will work with your Galil ACE.
VG6 Precision does not provide the outside diameter of their AR-15 Epsilon Muzzle Device. I would recommend contacting them directly for more information.
Yes, the VG6 Precision AR-15 Epsilon Muzzle Devices for 5.56/.223 will be compatible with your Ruger Precision Rimfire rifle which uses 1/2x28 threads.
Best to check with the manufacturer of your barrel to confirm the thread pitch of your barrel.
The VG6 Precision AR-15 Epsilon Muzzle Device 5.56 model will fit a Daniel Defense DDM4V7.
No, the VG6 Epsilon Muzzle Device is bored for 5.56/.223 (0.224"). 9mm has a bullet diameter of 0.355". You can use the VG6 Precision EPSILON 9mm Muzzle Brake, found by using the link below:
https://www.opticsplanet.com/vg6-precision-epsilon-9mm-muzzle-brake-compensator-flash-hider.html