Vacuum remelting is a purification process. Much like re-crystallization in chemistry, but in molten metals.
Some impurities gasify at less than atmospheric pressures when heated. So, you can get crap out of the melt that you can't get out at atmospheric.
C, Mn, S, other stuff.
It's considered essential for working with Ti.
It's for ultra purity.
Then of course, there's the solidification process (cooling), micro crystalline control is exerted over the melt.
Wonko was right in his comment that ruptured barrel threads die quietly, with no definitive conclusions.
People studied ruptured barrels extensively during the transition time from laminate to fluid, mandrel welded to drawn and bored barrel making. 2-piper cited Burrard 10 years ago, who did much of the studying.
In these threads about angels on pin heads, ultimately decisions are made by people saying, "It's good enough."
When a gun maker is 500 years old, and has been a leader in advanced manfacturing techniques for milions of firearms, people are looking at the wrong end of the horse for the "why".
Last edited by ClapperZapper; 06/05/16 09:03 PM.
