I was in the process of selling a barrel , keep it now, Just in case it goes wrong ,

Here is the Question, I am selling a barrel & the buyer asks " Is it straight "
Whilst I realise that no one wants to buy a bent barrel, How do you know , I have sold many.

The barrel in question is a HW, I have a few ,
Ok, I spun it up in the lathe, Held by the front of the barrel over its length & measured runout ,
It was about 1.5-2mm, out, So, I tested the other 2, One was slightly better & the other fractionally worse,
Next up Bsa Meteor, About 2 mm out, & Finally a Crosman 140 ,
It was dead straight ?

I came to the conclusion ( Rightly or Wrongly ) That these barrels are brazed into the Breech block , The Breech block is thicker on one side than the other & would pull on cooling to the thinner side ?
The Crossman barrel is a press fit hence no weld distortion ?

Does anyone have a couple of new barrels to test ?
Its intresting to know that a couple of guns suffer " Barrel Droop " After usage, Possibly taking a " Set "
I know ? What do you think, Ged.
Some Pics-