How much do you have to spend to get a useable bore scope that would work on everything from .22 pistols to long shotguns? I would rather not get it right on my third try.
I put the cable up the breech and magnify the image at the muzzle.
With that I can tell if a rifle barrel was lapped. The rough insides of a Remington, Winchester, Savage, Browning, Ruger, etc rifle barrel does not look like a mirror finish Hart, Lilja, Krieger, Shilen select match, etc.
I can only see a few inches of the bore, but that sampling is all I seem to need.