Bore Scope: What am I Looking At?

[raindog]

I got a cheap Teslong borescope as a gift. Pics aren't great but it was interesting to stick it down some of my milsurps.

I'm not entirely certain what I'm looking at, though. Click on pics for bigger versions.

Here's a shot from a Yugo 24-47 that was rechambered for .308. I include it only because the barrel has only been shot a couple times so it's pretty clean:



I think that's what a "perfect" bore should look like.

OTOH, here is a Mosin-Nagant M44. I'm guessing this is pitting from corrosive ammo?



Here is a 1926 Mosin Nagant...same issue I think:



OTOH, this Mosin Nagant 1938 Carbine looks pretty good:



And my 1968 Finn looks great:



Alas, my 1891/30 seems to have some rust and other unpleasantness...which is disappointing because at one point I cleaned the hell out of it and I've always done ammonia + cleaning after shooting surplus through it:

 

[Alaskan Ironworker]

Now Im interested in getting one, that looks cool as heck. What make/model/price is your scope?

 

[raindog]

Now Im interested in getting one, that looks cool as heck. What make/model/price is your scope?

This is a very cheap model. https://www.amazon.com/Teslong-Borescope-Side-View-Semi-Rigid-Smartphone/dp/B07TTQF24F

Plugs into my laptop. I believe you can also plug it into an Android phone but I don't have one of those.

The resolution isn't great (as you can see) but it's very easy to use. I think its main value would be to get a general sense of the bore rather than get high quality images. It actually looks better when the scope is moving and you're getting an impression rather than a still photo, if that make sense.

There are definitely, definitely better bore scopes out there but as something I got as a cheap gift it was interesting.

 

[Steve S.]

Neat photos to view - very telling.

 

[Dave DeLaurant]

Cool pics! Sadly, click to make big isn't working for me.

I can't offer much in the way of intelligent observations here, but a little more context might help others with interpretation

For example: which section of the bores are we seeing? Erosion from normal use (as opposed to abuse/neglect) should be worse nearest the chamber.

I don't really know how uniform primer corrosion is distributed, but that may also be worse near the breech. Anyone know for sure?

FWIW, I think the bore in the bottom photo may have been more roughly manufactured, before whatever attacked the inner surface. To me, those longitudinal features in the rifling grooves look like they were probably there from the start.

 

[SwampWolf]

Sometimes, ignorance really is bliss. If you can't afford to fix it or change it or it is entirely impractical to do so, with the caveat that the firearm under scrutiny is otherwise "sufficiently" accurate despite the warts, not knowing the "truth" can be the equivalent of a good night's sleep.

 

[scotty]

The question is how do they shoot? I have a 1903 Springfield that has sharp rifling but the bore is rather pitted. It looks a looks a lot like your 1926 Nagant. This is with my eyeball looking down the barrel, as I don't have a borescope. The pitting runs pretty much all the way down the barrel. If I do my part, it will shot very nicely. Sub 1" groups at 100yds with the peep sights that it has.

 

[Walkalong]

That's the Teslong I have and it works great.

Very dirty (Carbon from fast firing a lot of rounds in PRS matches).



After a thorough cleaning. And yes, the lands are getting washed out after around 1400 rounds, still shooting well though.

 

[JFrank]

Man I need one of those.

 

[Demi-human]

Man I need one of those.

They are nice.
Especially for the slim cost.

The resolution isn't great (as you can see) but it's very easy to use.

I ran a sewing thread alongside the scope camera and threaded the mirror over it. It keeps the mirror tight so that screwing it in and out will focus the tiny lens, and the thread keeps it there while I check out the bore. My pictures were clearer and much easier to use than tape.

As far as what you are seeing, yes.

All your observations are correct. Some pitting, some rust in one, “frost”(slight surface pitting well scrubbed out) in the 1938 carbine, and I believe the lower one is a coal mine, with just a few veins of copper ore.

Here’s one of the Coney Island board walk...

Still a 5/8” shooter.

 

[BreechFace]

And my 1968 Finn looks great:

View attachment 974296

Beautiful! Looks like it was just zambonied!

I've been more than happy with my Teslong. For the money they cannot be beat!

 

[Walkalong]

I ran a sewing thread alongside the scope camera and threaded the mirror over it. It keeps the mirror tight so that screwing it in and out will focus the tiny lens, and the thread keeps it there while I check out the bore

Cool.

 

[Walkalong]

This is the barrel of an expensive "match grade" bolt gun, very disappointing to see. Shoots better than it looks, but definitely not a match grade quality barrel, nor on paper either. It does shoot the famous "MOA" most of the time, but that isn't what one expects from a match grade gun/barrel. One expects much better. I could tell when I cleaned it that it wasn't smooth like it should be.

 

[Demi-human]

It’s not supposed to sound like a zipper when I clean the bore?

 

[herrwalther]

I have the same Teslong model and it works great. I have scoped a handful of my stuff and have diagnosed a few shooting problems that way. Mostly bores I thought were clean but weren't. It is almost compact enough I consider taking it into stores with me before I purchase something.

 

[Captcurt]

I have got to get one of these. I want to compare my M18 to some of my other rifles. It feels a slick as a gut when I run a tight patch through it.