Do you guys check for tight spots in your barrel

[Barryg]

Please tell me what you would learn by pushing a pellet down the barrel of an accurate gun

You could learn if the barrel had a loose area where air could pass the pellet but would not affect accuracy because of the choke only but could lose a slight bit of power and you could not remove the choke IF you wanted to for some reason.

Would you really knowingly buy a gun that had a tight and loose area in the barrel even if it shot ok.