Help needed to interpret Borescope of rifle bore

[TQB]

Hi,

I have a Steyr-Mannlicher Match UIT that is quite old (1982). It should have several thousand rounds through it.
I measured the COAL (touching the lands) to be 75mm (2.95") and CBTOL to get 60.08mm (2.35").

I'm not sure if that means a long throat by design if it is a sign of throat erosion.

I just got a Teslong Borescope and made these two videos.

Besides the need of a more through cleaning, do you see anything wrong?

Thank You,
Tiago

 

[varget204]

Looks like a little carbon build up at back of throat, a stiffer nylon brush & cleaner will remove it +elbow grease

 

[David Christian]

Scrub out the carbon ring then post another video. What makes you question the throat dimensions?

 

[watercam]

Clean it and shoot it. If it shoots well you're good. If not, buy a barrel. As simple as that. It would be hard to imagine a match rifle that old that had not been shot quite a bit.

 

[TQB]

What are your suggestions on bore cleaners?. I'm using Boretech Eliminator.

 

[David Christian]

Eliminator is a good start. Let it soak and then take an over sized brush to that carbon ring. You could also use your favorite paste such as Iosso to really clean up the barrel.

https://iosso.com/clean/products/bore-cleaner/

 

[WIB3]

After clean patches with eliminator, I use Flitz on a worn nylon brush. 5 strokes back a d forth. Does a fantastic job of removing carbon.

 

[boltman13]

Flitz + nylon brush repeat until carbon gone or you can't do it any more. After 2 or 3 bore scope it to see how much progress you have made. Good luck.

 

[Ledd Slinger]

By saying it "should" have thousands of rounds, does that mean you do not not know how many rounds it has and you are assuming it has thousands of rounds on the barrel?

From what I see on the videos, that barrel does not have "thousands of rounds" thru it. If it had thousands of rounds, you would probably see some fire cracking, the lands would start much further forward and the lands would also be way more gradually drawn out before you saw full groove depth.

Other than some carbon build up, that lands and rifling looks like it's in great health. Probably has nowhere near as many rounds through it as you think. Definitely looks like a long freebore by design to me.

Give her a good scrubbing and go have fun

 

[TQB]

By saying it "should" have thousands of rounds, does that mean you do not not know how many rounds it has and you are assuming it has thousands of rounds on the barrel?

From what I see on the videos, that barrel does not have "thousands of rounds" thru it. If it had thousands of rounds, you would probably see some fire cracking, the lands would start much further forward and the lands would also be way more gradually drawn out before you saw full groove depth.

Other than some carbon build up, that lands and rifling looks like it's in great health. Probably has nowhere near as many rounds through it as you think. Definitely looks like a long freebore by design to me.

Give her a good scrubbing and go have fun

You must made my day!
You're right I am just assuming. I was fearfull that it needed a rebarreling.
Accuracy wise it can get 0.5 MOA or a little bit better.
I will post some groups later.

 

[Longtrain]

I’ll agree with most that’s it’s a bit fouled. Carbon is the toughest to remove, I would use a good bronze brush and a solvent of your choice, Butch’s, Shooters Choice or Hoppe’s, 10 full passes, then patch it out until the gross powder fouling is gone. You may get false blue from the brush or a little real copper blue. Then take a worn brush and roll over it a patch or two covering it lengthways. You’re looking for a tight fit, then apply either Isso or JB paste over the patch. Again 10 full passes with some extra back and forth above the chamber area. Patch it out with your solvent, dry and scope again. Repeat as necessary (you will need to). Patches will come out black, part of the process. This will work, takes a little time and as said elbow grease.

 

[TQB]

Iosso paste is on my shopping list.

Some pictures. Very little wind.
First at 300m, but it was one of the few that was as tight.

At 100m while trying to find a load that works.