After waiting for months, I finally got one through Midway. The only
bad reviews I could find was one by a guy who left some cleaner in
the barrel which got into the lens, ruining it....so he gives the
unit a bad review (they should have made it idiot-proof!). The other
was by one who would have liked the resolution to be better, but
mine is fine. Perhaps it would be more noticeable if the view was
forward in the barrel instead of 90* to the lens.
I've only looked down the barrels of three rifles. Found chatter
marks in the grooves of a Sav 12, along with some small "pitting" or
otherwise deformities, yet it shoots great. Surprisingly, the
smoothest barrel I've come across is a RA Predator, with hardly a
thing noticeably wrong, yet it isn't as accurate as the Savage.
The worst barrel viewed is a Montana Rifle Company Model 1999 in
7mm WSM. No wonder I could never get it to shoot..." uneven lands
in the throat from being chambered crooked" is putting it lightly!
No lands for a ways on one side and barely touched lands on the
other! Had I had the Lyman borescope when getting that rifle (it's
been a few years ago) it would have immediately gone back before
ever getting shot and demanded my money back.
Yes, I've found a few interesting details, and am sure there will
be plenty more as I go through all my rifles.