Barrel without extension installed

[rob_s]

I know what the extension by itself looks like and can find multiple pictures online. I know what the tool to tighten it looks like and can find pictures of that too. I can even find pictures of the indexing pin alone.

What I can't seem to find is a picture of a barrel without the extension installed. Anyone have one or direct me to one?

[Quib]

A couple pics here Rob......http://http://ar15barrels.com/making.shtml