I recommend this OneTigris Rifle Borescope with Dual Lens, a tool for professional cleaning of gun bores of all sizes from .20 caliber and up. The 4.5" IPS LCD Screen allows for images and videos in HD resolution, this is much better than other borescope offerings that have you make use of your smartphone and an application.
This is a dedicated tool for the job and allows you to use your smartphone for what it is made to do. It has a backlight on the case and also a light for the probe end. In the case there is a vial that holds 2 probe hooks- 1 magnetic and one not and also a tool to eject the 32GB TF card to keep images and videos captured by the probe. Also comes with USB to USB-C charging cable, a savings in batteries. All items fit nicely in the zippered storage case.
The 78" flexible Probe tube makes inspecting rifle bores and handgun bores equally easy. Without a borescope I would run cotton patches through the barrel until no residue or burned gunpowder traces remained. Now I can inspect the bore with the forward and side view of the bore with the lighting OneTigris provides and actually see where the fouling resides.
The probe is waterproof and makes it possible to be used for other applications besides being a borescope. In your home checking for leaky pipes, you can introduce the probe into a small opening in the wall and locate the pipes that are leaking. This takes a lot of guess work out of the picture and saves you a lot of additional work replacing damaged walls you made while searching for the trouble spot.
There are other applications you could use it for like automobile work and other household purposes for the OneTigris making it a very adaptable and handy tool to own.
