INclusiOn

and "Sand Holes"
Shooting: Its Appliances; Practice; and Purpose, James Dalziel Dougall, 1875
http://books.google.com/books?id=-ToCAAAAQAAJ&pg=PA25&dq The “sand-hole” is a thorough flaw; and if the barrel stand the proof at all when it exists of any size, still it cannot be quite safe, as the hole will often run in a tortuous direction for a considerable length under the surface, being, as its name imports, full of fine sand, or probably of the powder used as a flux to promote complete adhesion in welding the barrel, which has adhered to the iron, and been closed upon in the act of forging.
That's why "rough forged tubes" are proved.And the idea that (properly fabricated) pattern welded barrels deteriorate over time related to internal corrosion/rusting has been proved to be totally bogus
https://docs.google.com/document/d/1ZnptAPvQIlWG5n5UU2FmKcFpYtVmOSc4b7K7G9IBs4g/edit BTW: Remington paid a lot of $ (mostly to the class action lawyers) over manganese sulfide "stringers" in AISI 1140 Modified barrels.
Loitz vs. Remington Arms, 1990
http://law.justia.com/cases/illinois/supreme-court/1990/68367-7.htmlAs did Savage recently related to the Savage 10ML II (designed for use with Smokeless Powder) with Crucible 416R Chromium Stainless Steel barrels. It is alleged that catastrophic barrel failures have been the result of both a design flaw and a metallurgical flaw; manganese sulfide inclusions in the 416R
https://cases.justia.com/federal/appellate-courts/ca6/12-1475/12-1475-2013-08-09.pdf?ts=1411028258 The big $s are in oil pipeline blow-outs and planes falling from the sky, and the NDT industry and Forensic Metallurgists are pretty good at figuring out why.
http://www.wsj.com/articles/southwest-incident-linked-to-cracked-engine-blade-1473716012 Fan blade was shown to have a crack by MPI and not replaced during maintenance
Dangerous world out there and just another reason why none of us need guns...or cars...or planes
