Quote Originally Posted by markm View Post
My assumption is that the land and groove relationship is parallel even in the tight spot. In other words, the groove is the same depth, but there's a narrow spot in both land and groove at the tight spots. But I could be wrong.
Hard to say, depending on how the barrel is made. I can only say the depth is not necessarily constant. Slugging will tell you both diameters. And of course everything is hunky dory if you just read the specs.

Traditionally riflings are cut. The bore is predrilled, and cutter is pulled through the bore to cut the grooves in multiple passes. Now there are many different ways to manufacture. But for handloading, with cast bullets especially, and gunsmithing, slugging and chamber cast are the standard methods.

-TL

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