I have a teslong for my iPad as well and couldn't be happier. Very useful tool.
Good point, out of curiosity I inspected by barrels and many others when I received my Teslong. Like someone else mentioned, it was a wake up call on what I thought I knew about cleaning and fouling. Since then, I inspect every so often for carbon build up then clean to remove fouling. I stop when the copper build up in the pits is gone, it varies how much cleaning is needed. Powder residue seems to be the easier to remove per my inspectionsOK, no more plugs for Teslong. But instead, a plug for PRACTICE. I spent a week looking at every bore I had, including several that shot poor, and the best, and everything inbetween. And a couple old barrels laying around....
You will not know what you are looking at , at first. I have not looked down a $500 plus bore scope. The Teslong gives really clear pictures. Not explanations! At first, its hard to know what are lands and rifling. You have to twist the scope gently and push back and forth slowly. And adjust the mirror sometimes.
All I can say is that, I saw stuff I never saw before, except in pictures in books and on the web. As noted, you will find guns that shoot that look bad, and barrels that dont shoot, that look fine. I *think* that there are the occasional home runs with a scope, like the pics I have seen where the reamer clearly did not engage the bore on the same angle.
Cleaning also is a win. Looking and learning what is "clean enough" has got to be a step forward. I suspect over time, there will be a greater knowledge base about this as well, better than the " I do 20 patches, letting it stand for 10 min each time" version of OCD that is out there.......