Tight spot in 20 ga Smoothbore

[Appalachian Harry]

Is the tightness gone?

The tightness is still there after doing the process again this morning but no rust...

I am stumped and not sure what to do now

 

[French Colonial]

Go on Amazon and buy a Teslong borescope. $50.00

Shove it down there and then you will know for sure what's going on.

 

[rich pierce]

As a builder, I unbreech in a case like this. If bought from the builder directly, I’d advise contacting the builder. A couple possibilities have been mentioned including a touchhole liner protruding slightly into the bore. I’d get the breechplug pulled by the builder or a flintlock gunsmith.

 

[Britsmoothy]

Just get a mop of wire wool down there and get scrubbing..
It's just a rust ring and won't affect nothing.

 

[Appalachian Harry]

 

[Appalachian Harry]

My borescope came in and it seems like my resistance spots are rust pits? And a lip of steel in the barrel

 

[Appalachian Harry]

Any tips for next step?...

 

[Britsmoothy]

Is that rifling?

 

[Appalachian Harry]

Is that rifling?

Nope this is an English Fowler 20 gauge smoothbore. But not sure why that’s in the barrel

 

[Appalachian Harry]

Maybe it could be where the octagon barrel transitions to the round barrel?

 

[Robby]

Might be interesting to slather a patch with naval jelly or Evaporust and it sit on the rough spot per directions.
Robby

 

[Britsmoothy]

Photo#2 looks like rifling ending in the breech??

 

[Appalachian Harry]

Might be interesting to slather a patch with naval jelly or Evaporust and it sit on the rough spot per directions.
Robby

Photo#2 looks like rifling ending in the breech??

Wouldnt the Evaporust be harmful to the finish?
Also it looks like that the breech but it not. There more barrel beyond it. First time using borescope haha

 

[Robby]

Wouldnt the Evaporust be harmful to the finish?
Also it looks like that the breech but it not. There more barrel beyond it. First time using borescope haha

From their web site.
I GOT A BLACK FILM ON SOME PARTS AFTER USING EVAPO-RUST®. WHAT IS IT, AND HOW DO I REMOVE IT?
The black film is carbon from the steel. Steel is composed of a combination of carbon and iron. In certain instances, steel will darken in color after rust has been removed from the surface of the metal. This is a natural phenomenon that chemists refer to as “carbon migration”. The carbon from the steel moves, or “migrates”, to the outer layer of the metal and settles into the pores. The removal of the rust (iron oxide) reduces the proportion of iron to carbon, leaving a higher concentration of carbon on the outer surface. This heavier layer of carbon could cause a darkening of the metal due to the attributes of the carbon. The darkening does not have an adverse affect on the metal. It merely represents the movement of carbon from the interior of the metal to the exterior of the metal.
Since Evapo-Rust® is a highly effective rust remover, it stimulates the carbon migration process. Evapo-Rust®is not alone in creating the carbon migration effect. Other rust removal treatments will also result in carbon migration and a darkening of the metal. The primary difference between Evapo-Rust® and the acid based treatments is that Evapo-Rust® will not harm or weaken the metal. Unlike other treatments, Evapo-Rust® will not darken products made with low carbon steel.
With Evapo-Rust®, sometimes a wiping with a dry cloth or a more rigorous buffing can remove the dark coloring. A quick rinsing of the metal after Evapo-Rust® has been applied may also keep the carbon from settling into the pores of the metal.
There are several things that can be tried to minimize the effects of carbon migration. First, high carbon parts should not be soaked longer than necessary. Once the rust has been removed, the parts should be rinsed and dried. Second, a further dilution of the Evapo-Rust® formula may have a positive affect. The lower concentration of Evapo-Rust® will take longer to remove the rust, but may have less of an effect on causing the carbon migration.
Robby

 

[Appalachian Harry]

So I know I need to remove this rust. Do I need to remove to pits as well? Any other methods (with or without EvapoRust) that other recommend on removing the rust and/or pitting?

 

[54ball]

Any tips for next step?...

As a builder, I unbreech in a case like this. If bought from the builder directly, I’d advise contacting the builder. A couple possibilities have been mentioned including a touchhole liner protruding slightly into the bore. I’d get the breechplug pulled by the builder or a flintlock gunsmith.

You have been given the best tips.....
putting a bunch of goo down the bore (that's pretty much a metal treatment/acid) is not a good idea. Have the builder unbreech it and check it.

 

[Robby]

So I know I need to remove this rust. Do I need to remove to pits as well? Any other methods (with or without EvapoRust) that other recommend on removing the rust and/or pitting?

The Goo, Evaporust, will remove the rust from the pits as well without harming the un-oxidized steel. Without a complete barrel honing the pits will remain, which will require being more attentive and thorough in your cleaning. I would also recommend removing the breech plug as well.
Robby

 

[sawyer04]

Yeah, this is what happens when hot water was not used and mineral oils used.
Get a wire wool mop fabricated down there and spin it via a pistol drill.
When you clean it next use hot water.

Well, Brits, you and me have got to go out back and talk about this hot water thing.

 

[Robby]

Probably should hook these together.
https://www.muzzleloadingforum.com/threads/steel-lip-in-flintlock-fowler-20-gauge-barrel.137298/Robby