Gents I have one of these digital camera scopes. Included here are 2 images as samples of what one can do. My scope has 7mm camera end and can view inside 223 chamber or of course 45-70s. This one is from Amazon ($35) and they can be reviewed at
www.supereyes.com The unit is available with 30, 45, 60, degree optic tips at extra cost. I installed it on old PC in shop. This unit's software, included, operates on Windows XP2, Vista or Win7. The software allows setting scales and measurements too. It is handy to view inside actions and could save disassembly. The unit covered in thread above with it's own LED display might be hard to see in sun light or field. I like viewing images on big screen monitor i.e. larger image without expanding electronically is clearer. One hint is both camera and object (rifle) need to be fixed down to get clearest images. Hand holding this camera except for viewing wiring behind a wall really shows your heart beat

This camera is in color so bore crud might be identified. Best feature is ability to record images for files and later comparisons, or forwarding to someone for info. Having such a tool is handy as two front shirt pockets.