Do military/industrial tubes sound better than regular ones ?

Well again, not being a tube guru, I may be mistaken by all of this, but in the time period most vintage tubes are coming from, wasn't their primary intended use to be industrial?  As in, for example, oscilloscopes and other types of equipment?

Yeah, no doubt, NASA grade, medical grade, scientific grade. But also for guitar amplifiers, organs, TVs etc.

There is discussion of what a military tube really is so I'll add my understanding.  Military tubes generally have a military designation like vt-231 and often have JAN (joint army navy) on the box or even on the base.    They were made for a military contract and are generally the same design.  For my amp, the VT-62 is the 801A.

So I don't give military tubes more respect unless they come with a reputation.  The 6SN7 tubes have been studied to death and many of the military tubes are considered great but not because they have a military designator, because people think they sound better.  

Jerry

Be careful buying " medical" and " instrument" grade tubes.  Especially 6922 as they were used in a lot of test equipment.   Many are not NOS , they were pulled from gear as it was phased out and replaced  by solid state.   "Pulls" as they are known.  Many of those tubes were robust and still tested as new when pulled.  Plain white boxes and weak lettering is a red flag. 

Military vacuum tubes are built to specifications that ensure resistance to failure in high vibration environments and tighter tolerances³. They are not necessarily for the military, but are manufactured to meet these requirements³⁵

^{Perhaps tighter tolerances may impact the sound, but I believe the ones labeled for the military are no different than the ones labeled for any other use, probably coming off the same line, only labeled differently.}