The EPC-9 does not utilize an AR15 pattern barrel extension. This means that the user cannot use a reaction rod or similar product to safely install a muzzle device.
To install a muzzle device without excess risk of damaging your upper receiver or barrel we recommend safely securing your upper receiver assembly in a barrel vice. (Note: in order to do this you may need to remove your handguard)
Once the barrel is securely mounted in a vice, follow the instructions for installing your specific muzzle device.