What's in the Box?

[ssgross]

Okie dokie friends. I have a rafter in the shop from which hangs my backlog of barrels and magazine tubes all prepped and ready to blue. Took me long enough. Still need to get some things organized in the shop. But, I figured I should have these Ithaca tubes prepped and ready too. I got them all stripped down. I'm going to boil to convert all the active rust, card, and see where we are at. Before that though, I need to be extra careful with the ribbing. Boy do these tubes ring!!! perfectly still!! we do not want to go and screw that up. So I was going to drill a vent hole, underside down by the chamber so it will be hidden to prevent any steam or pressure inside the sealed vent from blowing it out. Looking it over, there appears to be a screw - take a look at the second pic from the original post. Don't click, here it is again


Is this a screw to pull the ribs tight at the base, or is it a plug for a vent when it was rust blued at the factory? Didn't budge first attempt (I'm never too serious in the first attempt at a screw. Basically just checking if I'll get lucky). It's soaking right now before making another go. If someone is certain it's just a plug, I'll dill it out, rethread, and replug when I'm all done. Thoughts?

EDIT: HA! never mind. soon as I hit enter I went to try it and it came out like butter. It's a plug. Here is a close up with some more Damascus eye-candy of the original finish.