Some more borescope photos...
Here's a labeled image that I made for someone a while back who was wondering what you actually see with the less expensive models like the Teslong. This is the barrel of my 2007 model CZ 452 FS in .22 LR. (The tiny spots on the mirror are debris on the mirror, not on the bore.)
View attachment 968610
Here's the barrel of my 1950 model Remington 121. This barrel's internal finish is much rougher than the CZ and the lands are less pronounced. The gun is very accurate with open sights but I've never had a scope on it to really put it to the test. With open sights it'll shoot with my open-sighted CZs if not out shoot some of them.
View attachment 968611
Here's how a typical .22 LR barrel looks after a few rounds. This one is my CZ 452 Trainer. You can see the coating of wax and a lot of powder residue. Some loads are quite a bit dirtier than this.
View attachment 968612
Here's the same 452 Trainer barrel after a quick cleaning.
View attachment 968613
Here's my Armalite AR-10 barrel as received showing residue from factory test firing.
View attachment 968615
Here's my 1970 model Browning SA-22 barrel that was perhaps the biggest shocker that I discovered with the borescope. I had shot the gun quite a bit and found it to shoot about 1.5 MOA (about .75") at 50 yards with GECO Rifle, which I consider to be very good for a factory semi-auto. After getting the borescope I was dismayed to see the chatter marks in the barrel of this gun that I find to be very well built, and which has a great reputation for quality craftsmanship. Apparently they don't hinder accuracy, or if they do, it's minimal.
View attachment 968623
Here's another that was a major shocker for me. It's my CZ 527 Varmint barrel after about 100 rounds of various types of ammo over a year or so. Between outings I patched it out with nitro solvent and maybe a worn-out brush and more solvent patches until they came out clean, then oiled it. Then when I looked down the bore with the naked eye it looked fine. The last time I had it out prior to this borescope photo it was shooting .3" groups at 100 yards with Black Hills Reman 40-grain V-Max, and .5" groups with GECO Rifle Target (the GECO used to be priced at almost bulk ammo levels prior to the Chinese virus destroying the world), so I never thought that it might be terribly dirty. To say the least, I was shocked to see the borescope images. I cleaned it with 40x bore cleaner and eventually got everything out to a pristine bore, but wow! What a shamefully dirty bore, and I wasn't even paying enough attention to notice (or had my eyesight just gotten that bad?). After this, and other revelations via the borescope, I'm now MUCH more meticulous with my cleaning.
View attachment 968627