.44-77 and paper patch?

[Distant Thunder]

Before this I have use only Badger barrels on my centerfire rifles. My .22 was actually my first GM barrel and it shoots better than any .22 I've ever owned. I pretty happy with it.
This is my 1st centerfire Green Mountain barrel, but I have good things about them from many different people in the past.

Now that I'm going to use one there are a lot of people concerned about the quality of GM barrels.
I will inspect it and report what I find. I only hope it is useable!

I will measure the bore and groove diameters. I'll also check the bore to the octagon for concentricity as there seems to be some concern about that. I can't imagine that the octagon wouldn't be cut to the bore. Every Badger barrel I ever used came to me with the octagon cut before it threaded and fit to the action. Everything was worked to the bore and they all shoot very well and none are visibly off center!

My .22 GM barrel was round when I got it and I cut the octagon before it went to the gunsmith so that one I know was pretty close to concentric. How close is close enough?

If the rifling was too deep, over .004", couldn't the bore be lapped to reduce the difference between the bore and groove diameters? I'd hate to have to do that, but it seems it could be done if it is a small amount to be lapped out, .001" or less. Lapping too much could make it difficult to maintain concentricity.

I would think that button rifled barrels would be very uniform and concentric. As would be broached barrels like Badger's. Single point cut rifling would be the one that would have the most potential issues. Any thoughts on that?

Either way I sure hope this barrel checks out pretty decent, I'd hate to see my project crash and burn before it even gets going!