Barrel "rings"

[Enosiophobia]

Morning all. Going deeper and deeper down the reloading rabbit hole I purchased a simple endoscope just to satisfy my curiosity. As I was passing it through the barrel I began to notice these "rings" at various intervals down the barrel. At first I thought it was some sort of camera distortion but it's not. Any idea what these are and their cause?


Gen 3 RPR
6MM Creedmore
Approx. 200 rounds

 

[rogn]

Can you tell if they are physical rings or optical effects. The "straightness" of a tube can be determined by difraction patterns which are optical "rings" in the view thru the tube. Concentric is straight, directionally biased shows direction of bending.

 

[ebb]

I don't know what the rings are, but if you had ever looked through a Hawkeye borescope you would not waste your time with that. Look at the bore with a real borescope and the picture will be so different that maybe it will be obvious what the rings are.

 

[FrankG]

As has been previously said....you need a better bore scope.

What you should be asking yourself as well....does the rifle shoot good? If it shoots good and doesn’t lose accuracy after say 15-20 rounds of being fired....shoot the gun till the barrel is junk and then replace it. If it’s shooting good don’t start buying miracles cures that are out there to make it better. You might make it worse.

Factory Ruger RPR barrel in 6 Creedmoor your going to be replacing it around 1500 rounds. It could go more and it could go less.

Later, Frank
Bartlein Barrels

 

[Enosiophobia]

I will be upgrading my optics as soon as my budget allows. This is what I have at this point. They're not optical as they remain fixed when the scope is moved in and out. Barrel shoots just fine. No complaints, just curious.

 

[FrankG]

It shoots!

Are the rings consistent along the whole length of the barrel? They run around the diameter of the bore and groove correct? Are they in the grooves as well as on tops of the lands? If they are in the grooves but don’t stand out as much as the ones on tops of the lands then most likely they are marks from the bore reamer when the barrel got reamed.

 

[butchlambert]

A borescope is a barrel makers best salesman.

 

[dcali]

See if you can find someone with a hawkeye with a 90 degree attachment. I'm curious too. Never seen that.

 

[dolek]

Just shoot it and enjoy it,looks like it is just fine by looking at the target.

 

[MGYSGT]

Good enough to see the copper and carbon.

 

[Doug Beach]

Why does it look like a 10 groove barrel?

 

[Webster]

Morning all. Going deeper and deeper down the reloading rabbit hole I purchased a simple endoscope just to satisfy my curiosity. As I was passing it through the barrel I began to notice these "rings" at various intervals down the barrel. At first I thought it was some sort of camera distortion but it's not. Any idea what these are and their cause?

View attachment 1106232
Gen 3 RPR
6MM Creedmore
Approx. 200 rounds

What does it look like in a small diameter pipe? It has to be an optical effect. It doesn't look like it has depth, just bright reflection. Does the ring move when you move the endoscope?

 

[Straightshooter1]

Morning all. Going deeper and deeper down the reloading rabbit hole I purchased a simple endoscope just to satisfy my curiosity. As I was passing it through the barrel I began to notice these "rings" at various intervals down the barrel. At first I thought it was some sort of camera distortion but it's not. Any idea what these are and their cause?

View attachment 1106232
Gen 3 RPR
6MM Creedmore
Approx. 200 rounds

Seems to be a reflection of the source lighting. If so, you can tell as those rings remain the same distance away as you move the scope in or out. I have a same kind of optical effect with my scope.

 

[Enosiophobia]

The endoscope has a light on the end so if it was the light it would move with the camera. It doesnt appear to be a "groove" but its visible. They appear every few inches at various intervals. I suspected they're from maching but I'm no gunsmith.

I just got it to see what the copper buildup looks like. Its 5R rifling so that's why it looks "weird".

 

[fyrewall]

Possibly a better view might provide a better answer, like a real good bore scope. There is natural phenomena called interference rings where light gets reflected or hugely bounced around inside a shiny tube resulting in banding & dark rings. Normally rifling, like lands & grooves or certainly a fouling deposits would absorb or breakup the reflections and prevent formation of the rings. Possibly, your endoscope provided enough light to make some kind of observed radial reflection - those rings are not interference rings. An example of interference rings would occur at your local hardware store and viewing a light source thru an aluminum tube having clean shiny insides - or your nicely cleaned 12 gauge smooth bore.

Ten lands & grooves is sure funny - how many lands & grooves does the barrel actually have? I assume that is a 200 yard target.

Edit - not scatter, like blue sky but interference like alternating bands - lots of reflection - I think the radial reflection came from your endoscope.

 

[Enosiophobia]

100 yard target

 

[Ggmac]

Morning all. Going deeper and deeper down the reloading rabbit hole I purchased a simple endoscope just to satisfy my curiosity. As I was passing it through the barrel I began to notice these "rings" at various intervals down the barrel. At first I thought it was some sort of camera distortion but it's not. Any idea what these are and their cause?

View attachment 1106232
Gen 3 RPR
6MM Creedmore
Approx. 200 rounds

Can you feel the rings when cleaning with a patch ? I'm leaning towards optical but clean the barrel and recheck , mark the location .

 

[Webster]

Morning all. Going deeper and deeper down the reloading rabbit hole I purchased a simple endoscope just to satisfy my curiosity. As I was passing it through the barrel I began to notice these "rings" at various intervals down the barrel. At first I thought it was some sort of camera distortion but it's not. Any idea what these are and their cause?

View attachment 1106232
Gen 3 RPR
6MM Creedmore
Approx. 200 rounds

I'm not an expert on making barrels but I beieve the procedure is as follows.
1. The barrel blank is drilled.
2. The drilled hole is reamed.
3. If it's cut rifling a cutting tool is pulled thru the bore while it's rotated. I assume it cuts both land and grooves. This cutting would remove any reamer marks.
4. Next the barrel is lapped with an abrasive by pulling the lapping compound back and forth in the bore. No rotation. All scratches straight down thee barrel.

 

[L.Sherm]

I'm betting Frank hit it, drill Mark's that the bore reamer never completely removed.

 

[Webster]

I'm betting Frank hit it, drill Mark's that the bore reamer never completely removed.

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.