Chuck - the engineering info you present is both spot on and quite correct. I would not, however, rely too much on it in the context we're talking about: a bulged barrel. The long and short of my reluctance (or objection) is that the information you're presenting is derived from carefully prepared laboratory tests run under controlled conditions. OTOH getting a gun to the stage of having a bulged barrel and now deciding whether to use it are not. They don't even rise to the level of a shadetree gunsmith tying a gun to a spare tire and firing it with a rope to see if it will blow up.
Other than illustrating ... something ... comparing a double with a bulged barrel to a Model 12 or other single-barrel is inapposite. There's a lot more going on with the double particularly, as noted above, under the ribs. Moreover, comparing this gun - with the bulge in the area of highest pressure 1/2 inch past the chamber - to any gun with a bulge near the muzzle - the low-pressure end - is likewise inapposite.
If the gun in question is to be used, it needs to be rebarrelled. Period. If that's too pricey, the guy intending to use it should price hand surgeons for comparison, then think again.
Dave,
Engineering data is practical application data. There are qualifications for its use. I mentioned a principal qualification...being crack free. One I didn't mention was measurement for elongation. That data can provide good perspective on where the metal is on that stress-strain curve (how much strain has occurred). This is all factual data and people put their lives in the hands of this applied data when using engineered products every day.
However, if people don't have a good understanding of the data, it's qualifications, and confidence in applying such data, they shouldn't. In the case of a barrel bulge, a layperson may not have the knowledge to understand what is necessary to make the assessment of the actual condition of the metal or select and apply the appropriate data. , That's to be expected.
What surprises me, particularly on barrel bulges, is the perpetuation of heresy as fact, when actual engineering data is provided.
