I just read the other comments to which you refer, and I must admit, I never have considered the issue from their point of view, either. So, I learned something here, today, too. My interest is to make sure that the recoil is taken by the thicker wood behind the barrel, and not by the thin tang, or tang bolt above.
As for the extra material at the rear of the barrel, its no different than providing a taller front sight than required, so that the owner can file the sight down to his particular load's "zero".
the first barrel I tried to match to a breechplug, I measure the length of the threaded portion of the plug, and then the depth of the threaded portion of the back of the barrel. I think there was about 1/8" difference in the two. I even called the barrel company to ask about that. I felt like a total stupid jerk when the lady said something like, " Why, we leave extra metal back there because we can't possibly know what brand or kind of breechplug you are going to put in OUR Barrel! Gunsmiths know this." As if it were common knowledge. The gun builders here must know it, because that is what they do when marrying a barrel and plug to a stock. I don't know where they learned. I still haven't asked them.
I am sorry about the tone of that comment. I took a couple of formal shop classes to add to the training I got from my father in using tools, and machines, when I was in high school. When I begin working in my shop, a short steel rule goes into the pocket of my shop apron, an old micrometer goes into the big pocket in the apron, and a pen or pencil goes in along side the ruler in that upper pocket. I never try to put any two pieces of metal together before testing them with simply finger turning, and then measuring them if that does not work.
I thought my first breechplug had the wrong thread, because I could not turn it into the barrel's threads by hand. After ordering and trying a couple of replacement plugs, I turned that barrel over to someone with more experience, because I was convinced I was doing something Wrong. He fitted the plug to the barrel and returned it to me. He said it was the correct thread, but the treads were cut by different taps, and dies, and they would only go together with lots of oil, and the use of a good wrench. He understood why I didn't want to force anything, and tried to make me feel better about the whole deal. I may have to remove that plug to drill the vent hole in the barrel, but at least now I know what to expect. I haven't checked that barrel since I got it back from him, (I set the project aside, and just have not gotten back to it)to see if I need to file down the back of the barrel. Its a .36 caliber rifle, so I don't plan to do so, unless the sides of the barrel that will butt against the stock look too slim.
Thanks for the comeback.
