I've been running all kinds of experiments on bore interiors in the last dozen years I've had a bore scope. Some important learnings I thought I'd share:

1) The only thing that REALLY matters is how it shoots. The rest is just academic.
2) The only thing that removes carbon fouling is elbow grease. How much elbow grease depends entirely on what you mix it with.
3) If the mixer isn't some kind of abrasive, bring a lot of elbow grease.
4) Patch color tells less than I originally thought about the cleanliness of the bore.
5) You can hide a lot of copper under one thin coat of carbon. Pennies and pennies worth.
6) The old yarn about "beware the man with one rifle" was legit.
7) Which one is a question I don't believe I'll ever be able to answer.

I discovered all that without a borescope.I knew that it shot well when it was clean and tried everything you mentioned to get it clean.

I've never been accused of being a quick study. How you figure out #5 with out a borescope or X-Ray vision is a few IQ points beyond me.

That's easy, when a patch shows no color and your rifle still will not shoot after only 5 magnum rds fired ,that means there is copper that is still left inside.There is not enough carbon fouling after 5 rds in a new barrel that cannot be removed with a couple of patches of ordinary solvent.You can pass JB on a patch on a jag after only three 7mmRem mag rds from a new match barrel and then run a patch with a powerful copper solvent like CR-10 or Sweets and get no blue but your rifle will still not shoot unless you use JB on a brush and alot of elbow grease.

Under the circumstances you describe, it was usually never clear to me if...

1) My alter ego "Shitty Shot" had pulled the trigger.
2) My scope had died.
3) My bedding or action screw tension was at fault.
4) My powder throwing was from the special olympics.
5) The god of wind gusts screwed me again...
6) etc etc etc. I'm sure you get the point.

With a bore scope, if it's carbon fouling, the eye doesn't lie. You see it. One of the other myriad things that go wrong from the bench might exacerbate it, but you can at least say with certainty that you've got that problem at a minimum.

I have encountered all those problems you described over the years that I've been shooting.That what has made me the shooter that I am today.I know the eye doesn't lie but the brain is king! I am considering buying a borescope to learn more about bores and accuracy.I have a few rifles in the same model and caliber but some shoot better than others.I feel that a borescope would show me why.

Stuntpilot,

These cleaning observations have been really intresting and just brought up a though.

I am wondering how much of the throat wear we hear about might not be a big carbon build up that is really just coming apart? Have you ever taken a rifle with a seemingly bad throat and tried these super cleanings your talking about? Is it possible that a number of our shot out barrels are not shot out but rather superbly carbon fouled?

Don,
I try not to speculate about things I haven't actually seen. Since I've never let carbon build up very far in any of the barrels I've burned through, it'd be hard to answer your question directly.

I'd offer that the throats on the stack of Hart barrels I've shot out have the distinct look of a dried up lake bed. The internal surface topography of those eroded throats (most with 2000+ rounds of hot loaded 300 Win Mag through them) looks significantly different than the carbon buildup I mentioned previously as it began to flake off at the edges. Visually, there appears to be much more "depth" to the cracks of the "lake bed effected" steel than to the edges of the carbon fouling as it was chipped away from my cleanings.

I have no idea whatsoever if or how that appearance difference would translate into accuracy coming or going. It would be an interesting test to run, if one that's a little hard to establish a control for...

A nice trick that lets you see the inside of the bore just at the muzzle end is to insert a Q-tip about an inch into the muzzle.When this end is clean I assume my barrel is clean because this area recieves much less cleaning action than the rest of the bore.

I used the Q-Tip and flashlight inspection trick too until I got the borescope. Then I learned that the throats and muzzles of most of my rifles fouled and cleaned up like they lived in different zip codes.

I've wondered if the two endure significantly different internal combustion physics, even though they're only separated by 18-32"

One can see the throat of his chamber by looking down the action from behind the stock.If you clean your rifle like you are supposed to the chamber,throat and lands will appear like they should appear,thickness,sharpness,etc...If there was excessive carbon fouling I doubt that it would not be visible by the naked eye.I've been told by my gunsmith and believed this all along that you can wear out your throat and lands if you are too agressive with your cleaning.Just see how hot the barrel gets after short strokeing with Jb for a half hour or so.If you are a strong guy and you keep at it I believe you could turn a rifled bore into a smooth bore,taking what little carbon fouling there might be along with it all in a single cleaning.

quote:

If you are a strong guy and you keep at it I believe you could turn a rifled bore into a smooth bore,taking what little carbon fouling there might be along with it all in a single cleaning.

I'm not sure that belief dovetails with my observations down the borescope.

It's a common enough sentiment though. One I touched on in response to a good question from Kyler Hamann here:
https://forums.accuratereloading.com/eve/forums/a/tpc/f/645100744/m/112109616

Having been a guy taking notes with a borescope over the years certainly doesn't make me the world's expert. Just someone who's trying to inject a little hard data into a discussion that often lacks for it.

As for why I haven't yet seen even the smallest indication of any of my rifles turning into smooth bores from JB cleanings.... Maybe I'm just not that strong a guy.

That seems to be the problem.

quote:

Originally posted by shootaway:
That seems to be the problem.

Congratulations! The votes are in! Between that post, and your series of contributions on the African Memory Box thread,

https://forums.accuratereloading.com/eve/forums/a/tpc/f/1411043/m/980101716

you've won the award...