Barrel "rings"

[dstoenner]

Why does it look like a 10 groove barrel?

My thought exactly.

 

[Bc'z]

5 are lands 5 are grooves.
It looks like powder residue between the lands ,but probably just shadows
I'm thinking it's time for some JB's

 

[butchlambert]

100 yard target

Hate to say something to a person with that sign in name. You say .21MOA? I assume you aren't counting the one to the far left.

 

[L.Sherm]

Reamer marks shouldn't be a perfect single circle on top of a land and adjacent groove. Cutting grooves removes material. If it was reamer marks why would it be a perfect straight line circle. A reamer and drill are pushed forward as they cut, they don't cut in a perfect circle. I examined machability tool marks on a microscope at a research center Machinability Lab. The marks are too perfect to be from a reamer or drill bit cutting as it moves forward. Why isn't there other marks nearby? Because it's a light reflection. The OP should get a piece of steel tubing from a hobby shop and see what a smooth suface looks llike.

They will be in the groove and top of the lands on a button pulled barrel it there not remove before the button is pulled.

 

[butchlambert]

They will be in the groove and top of the lands on a button pulled barrel it there not remove before the button is pulled.

Little confused about your response. Are you saying that if it is in the reamed barrel and will show this if it isn't removed before rifling?

 

[fyrewall]

Thank you for starting this thread - lots of discussion - powder residue !

I corrected my post about the rings - an explanation of which can be found in Wikipedia.

 

[Doug Beach]

5 are lands 5 are grooves.
It looks like powder residue between the lands ,but probably just shadows
I'm thinking it's time for some JB's

I count 20 “features”. It’s either a 10 groove barrel, or there there is some optical illusion.

 

[butchlambert]

Look at the ring again. It is round! If in the barrel, it wouldn't jump across the groove from land to land as pictured. It is definitely an optical thing.

 

[Crosshair1]

It looks optical, once inside of the circle the detail is much more in focus.
Something like a mini 'contact lens' stuck to the main lens...

 

[L.Sherm]

Little confused about your response. Are you saying that if it is in the reamed barrel and will show this if it isn't removed before rifling?

Yes, if ring is not removed before button is pulled it will be there after.

 

[Bc'z]

I count 20 “features”. It’s either a 10 groove barrel, or there there is some optical illusion.

You sure do.
5 lands
5 grooves
10 black streaks at the corners of the 5 grooves.

 

[butchlambert]

Yes, if ring is not removed before button is pulled it will be there after.

So, where does the ring come from? It was not from the reamer. If it was a button barrel, and it impressed the ring, it would not be a "perfect" circle after the button was pulled through it.
I'm not familiar with the hammer forged barrels, but the more I look at it the more that I'm sure it is an optical thing.

 

[L.Sherm]

If theres a ring left by machining whether drill or reamer and not taken out before pulling the button it will still be there after. I'm sure Frank has seen it or he wouldn't have mentioned it and I'm sure Stan has too.

 

[Bc'z]

So why does the ring go over the top of the black streaks? You would think it would be broken at those points.

 

[L.Sherm]

It could very well be an optical ring all I'm saying is rings can be in barrels from the drilling or reaming process. Without a good borescope were all guessing.

 

[Shinbone]

Looks like an optical or digital artifact, to me.

 

[Bc'z]

I guess the only way to find out what it is, would be to split this baby down the middle.
All in the name of shooting science!

 

[butchlambert]

It could very well be an optical ring all I'm saying is rings can be in barrels from the drilling or reaming process. Without a good borescope were all guessing.

Well, I never seen rings like that from any drilling or reaming and then had rifling either cut or button rifled.
I would wager you that it is optical. Stan, where the 'ell are you?

 

[Enosiophobia]

My apologies for the range buddy pic. I forgot to change the settings. It was at 250 yards so correction is .38 MOA. 1 on the left, 4 on the right.

Here's some pics with a light source in the chamber and the camera light on. I can tell you with total certainty that when I move the camera, the rings do not move. If it was optical, it would change location / position with the light source yes?


I know these are still pics but when I move the camera in and out, they do not move.

As far as my screen name, no one liked it so I had it changed. Hope it's better.

 

[fyrewall]

For sure this is an cameral caused optical effect, most likely from the endoscope that needs some kind of light to see. Possibly, some definition boundary generated and used by the camera or light projected out from the camera - stuff outside the ring is blurred. Should this be some sort of cameral definition boundary or light projected from the cameral it would be fixed in relation with the camera lens and move with the camera. Again, focused inside ring, blurred outside ring. The big white blob is larger in the bottom photo than the top - I take it that the camera was moved towards the chamber and the ring is moving with the camera. Fish eye effect?

Want to see optical rings (light and dark bands)? - look thru your nice clean smooth bore (no fouling, no rifling) shot gun barrel at a light - interference rings - reflection - light, constructive - dark, destructive. This is not an optical effect due to light reflection inside the bore.

Next step should be inspection with a good bore scope.