Anybody ever tried one of the cheap ($20'ish) USB borescope/camera/endoscopes on their rifle?
Seems like it might work. They attach right to your smartphone, or computer, so you are not paying for a screen/reader like with a Lyman.
One issue would be getting one with a small enough head diameter to fit down a .22, or 5.56 bore.
The smallest I've found on line--in the sub $100 category--are 5.5mm . In theory, that would fit.