GSG 5 equiped with a Navy Picatinny rails handguard.
Same with a Finnish ASE silencer.

with retractable stock and silencer

Is the barrel itself threaded under the factory flash hider? I can't tell from the 1st page if it is the reflection or the barrel is actually threaded far back.

No. The silencer uses the flash hider existing thread.

Sorry I should have been more specific.

On page one where you have the pictures of the factory flash hider on the rifle, it kind of looks like the barrel is threaded under the front site post. Maybe that is just the reflection from the camera.
So the barrel is smooth all the way and has no type of threading on it? The flash hider is actually threaded on the outside. correct?

thanks

Correct, this is the reflexion of the front sight post thread.

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