My carbine is a "put together" project from parts I've had lying around for some time now.  The receiver is what I would call in excellent condition but I don't know if it originated from a carbine or a rifle or was ever used at all.  My hunch is it came from a rifle.  All I really need to finish the project is a barrel and barrel band.  I probably also have some work to do on my sights to make the the 01 or 02 usable.  Which all gets back to my question about Criterion barrels, or any barrel that would need the front sight installed.  How do you do it?  Or maybe better yet, is there someone I could send it to?  Thanks again guys, I appreciate your help!