Undeniable Borescope diagnosis

[Varminterror]

Polling the peanut gallery for experiences here...

What problems have you undeniably and by no other means identified and been able to solve because of a bore scope?

The common context: a rifle which shot well, no longer will. Guys run a borescope and see copper fouling or a washed leade, and recommend pushing out copper or replacing the barrel, respectively. In the former case, maybe things improve, maybe not. In the latter, assuredly things change, but it doesn’t particularly satisfy that excessive throat erosion is proof the barrel can no longer shoot well.

Note - I am not asking for a report of what “ugly things” you’ve seen in a bore when scoping a rifle with an otherwise unidentified issue. We all know when you run a borescope into a bore, you’ll see anything and everything from carbon or copper fouling, rings in the barrel, fire cracking, “grease slicks” of copper streaks, washed lands, chatter, pitting, etc. However, my challenge is that I have rarely found a significant and undeniable correlation between these commonly observed “defects” and performance on target.

I’ll go first: the only issue I can say after 20+ years of owning and regularly using borescopes that I can definitely identify, diagnose, and confirm as resolved with no other means than a borescope has been a carbon ring in the chamber.

 

[Varminterror]

Background - for those so intrigued as to why I ask:

I had a conversation this week with a friend/fellow PRS competitor. He squibbed last week and stuck a bullet in his match rifle. He took the rifle to a local smith, not a PRS familiar smith, to have the bullet removed. After removing, naturally, the smith scoped the bore, and noted to my friend considerable copper and carbon fouling, and asked how he was cleaning - ultimately recommending he push out copper and carbon every 50 to no more than 100 rounds. For those familiar with PRS, this simply isn’t possible, let alone sensible, as we might run 250-300 rounds just in zeroing and confirming velocity for and subsequently shooting a single 2 day match.

So my friend asked my experience with a borescope, and if it would be a good “investment” for him. Considering his financial state AND his need as a shooter, not a gunsmith, I couldn’t tell him any reason he should own a borescope, as I couldn’t identify any condition where a borescope would diagnose anything which couldn’t be identified by simply cleaning the rifle.

This morning, I noted a thread here in which a rifle which formerly shot well no longer would, and at least one user recommended endoscoping the bore...

Thinking about that conversation this week with my friend, I recalled back to how many barrels I had scoped AFTER NOTING AN ISSUE in a root-cause-analysis type effort, but also recalled many barrels I have scoped which had no issue at all and shot incredibly well. I can’t say that I find firecracking, copper or carbon fouling, rings in the bore, copper skid marks, firecracking, or throat erosion (etc) to be significant indicators of any particular issue, and when an issue DOES arise, simply cleaning the bore is as successful in diagnosing AND correcting excessive fouling as a root cause as bore scoping ever is.

I do know I can identify a carbon ring, which may not be corrected with a conventional cleaning without special attention to the chamber neck, and as a smith of sorts myself, I will always have reason to own one, but I’m scratching my head as to why I should defend a scope as a valuable tool to the typical shooter, even a competitive shooter.

I know when I scope any factory barrel, or any barrel with more than a couple hundred rounds through it, I could take a photo of something “ugly” to which an unscrupulous smith might point to convince an owner to pay for work to be done. But I also know I can see pitting, chatter, firecracking, throat erosion, rings, etc, and still see a rifle print ridiculously small groups, so none of these “ugly things” appear to have a true correlation to performance. So I’m asking myself - why the hell are we spending time scoping?

 

[earlthegoat2]

Define "peanut gallery" please.

I will have a go at this since I don't plan on actively answering the OPs question, I would consider that pretty "peanut gallery"

I don't and have not used borescopes for firearms and I probably never will as more than just a novelty. I have used them for mechanical repair and maintenance though. Often enough that I have concluded that all a borescope does is confirm what you already know.

I other words, folks who have a lot of experience in certain areas where borescopes might be needed (or are marketed towards) may not actually need them.

Fore instance, I was doing some work on a customer's chainsaw. I got done and I decided to check the top of the piston with a borescope (more as a novelty than anything) and I found a few pockmarks on the top of the piston. I wasn't too concerned since I had seen this before but only by shining a flashlight down the spark plug hole which gives much less of a view of the top of the piston. I noted it to the customer who didnt seem to care. Fast forward maybe 6 months and the same customer came in and needed some other work done. I got it done and out of curiosity checked the piston with the borescope. It looked identical as before and was apparently providing good service to the customer. It was an MS460 for those who are curious and are pretty popular with the timber companies around here.

Apparently what could have been perceived as a problem through a borescope really wasnt after all.

Sounds just like your friend and his gunsmith.

 

[Walkalong]

Some ugly barrels can shoot pretty well, and after 1K rounds I could show you some ugly with a bore scope and tell you that is your issue, but it would almost surely not be the issue.

I used to "feel" it with patches run through the bore, now I can see it with a bore scope. A dirty or rough from shooting barrel didn't cause a squib.

I saw the damage in my buddies barrel right before he finished well in a one day PRS match last Saturday. Lands washed out right past the chamber, and I mean gone, fire cracking the first third of the barrel, but the second half looked pretty good, with the last 1/4 looking very good with a nice crown. The groups had opened up when testing prior to the match, but not terrible.

I really like having the bore scope now so I know exactly how clean or dirty the barrel is, but it will take a long time looking at barrels with to to draw any conclusions about what is bad and how if affects function. Accuracy I can tell, that's easy, just shot it.

I proved to myself long ago that a barrel with damage in the beginning of the barrel can still shoot well for a few rounds if you get it clean.

The squib wasn't because of a dirty or worn barrel I'll bet cold hard cash on that.

 

[mcb]

A quick way to identify a bad chamber. If the chamber is not concentric with the bore it's pretty obvious in a bore scope, though really only valid for new barrels since shooting it would show an accuracy problem right away. Gas port erosion and alignment is monitored well with a bore scope but that is not all that useful for a PRS bolt gun. I have never found a visual indication of clean to be super valuable. I have shoot good groups with horribly filthy bores.

 

[jmorris]

I used to "feel" it with patches run through the bore, now I can see it with a bore scope. A dirty or rough from shooting barrel didn't cause a squib.

I agree with this. “Dirty” won’t cause a bullet to get stuck and bore scopes are just another tool, not magic wands.

I use them more for looking into engines than anything else, not that I couldn’t take them completely apart and see what I can on the screen, it’s just faster.

 

[BreechFace]

Why not own a bore scope? One can be had for $60 these days.

OP question seems moot given the parameters. Given the fact that PRS shooters spend that much in no time at all in their activities.

I guess that’s my “peanut gallery” response.

 

[Garandimal]

Polling the peanut gallery for experiences here...

What problems have you undeniably and by no other means identified and been able to solve because of a bore scope?

The common context: a rifle which shot well, no longer will. Guys run a borescope and see copper fouling or a washed leade, and recommend pushing out copper or replacing the barrel, respectively. In the former case, maybe things improve, maybe not. In the latter, assuredly things change, but it doesn’t particularly satisfy that excessive throat erosion is proof the barrel can no longer shoot well.

Note - I am not asking for a report of what “ugly things” you’ve seen in a bore when scoping a rifle with an otherwise unidentified issue. We all know when you run a borescope into a bore, you’ll see anything and everything from carbon or copper fouling, rings in the barrel, fire cracking, “grease slicks” of copper streaks, washed lands, chatter, pitting, etc. However, my challenge is that I have rarely found a significant and undeniable correlation between these commonly observed “defects” and performance on target.

I’ll go first: the only issue I can say after 20+ years of owning and regularly using borescopes that I can definitely identify, diagnose, and confirm as resolved with no other means than a borescope has been a carbon ring in the chamber.

In the ethereal realm of Sub-MOA/Long Range paper-punching... I'm sure the problems of bore are monumental.

For "Minute-of-Dinner" hunters like me... not so much.






GR

 

[rbernie]

I use a borescope to help me determine initial barrel quality, and to watch the condition over time. I've never used it to troubleshoot an issue.

 

[JJohnston015]

I've had my first borescope for a month or two now, and you may be right - I'll probably never use it to diagnose trouble, but I HAVE already used it to tell me when I'm done cleaning; no longer will I go by that old (and indirect) advice "when the patch comes out clean". Now I can clean until the bore is clean.

I can't agree with your position that they're not justifiable, not when a good one is available on Amazon for $40. At the very least, pictures of a clean bore lend credibility, and may even increase the final price, when you post a gun to an auction site. It seems to have worked for me lately. Possibly it paid for itself.

 

[Chuck R.]

Like others I use mine primarily for the 1st couple cleanings, until I can get an idea what that particular barrel requires to get it where I want it to be.

I paid right around $40 for mine that works through a tablet. Didn't exactly break the bank.

The only rifle I've ever used mine on to diagnose had already declined so much in accuracy it was more of a confirmation. The borescope does make me feel better about spend $$ on premium barrels though.

 

[Varminterror]

The squib wasn't because of a dirty or worn barrel I'll bet cold hard cash on that.

I apologize for lacking clarity earlier - of course the squib wasn’t caused by anything a borescope could see...

But rather the squib was the reason the smith decided to borescope the barrel, after which he commented on the “poor state” of the barrel, that it was copper fouled, carbon fouled, and the leade washed - and instructed my buddy to clean after no more than 100 rounds to prevent that “poor state.” He only borescoped the barrel really to confirm his work with the brass ram rod clearing the bore hadn’t done notable damage.

But in scoping, he commented on all of the ugly things present... the ugly things my buddy had been putting into .3-.4” groups and single digit SD’s with stable velocity... but hey, it’s ugly in there (a 6BR with ~1500 on it).

 

[Nature Boy]

The only thing my borescope does for me is tell me when my barrel is clean

As far as correlating some artifact I’m seeing with accuracy issues I would have to say that exceeds my pay grade.

 

[earlthegoat2]

Affordable, cheap, inexpensive....does not make it justifiable.

I paid nothing for mine and I have no use for it but pure novelty.

 

[243winxb]

I used to "feel" it with patches run through the bore

Carbon
Same here, when i tried not brushing to save the barrel.

 

[GooseGestapo]

Me and my aircraft mechanic just saved a new client about $60,000 on an airplane he’d bought, with a borescope.

Several other shops had assessed the engines and stated it needed both engines re-done (Cessna 340). Reviewing the log books revealed that the engines had 4hrs on them! Since remanned by Ram aircraft engines 4yrs ago! Plane had sat in a hangar for 3yrs without annual inspections. Bought at auction for penny’s on the dollar.

Engines have not been even broken in. Ram used Nickle Nitrided cylinders which require substantial break in. Cylinder bores and valves look brand new. Because they are. Five of the twelve cylinders have low compressions.

BTW, the mechanic let’s me use his laboratory grade bore scope on occasion to inspect barrels... too.

 

[JFrank]

@Varminterror
Without going into four paragraphs of useless blather and lifelong background please tell us little people in the gallery why in the world it takes 250-300 rounds to zero and dope a rifle that you’ve already been shooting weekly or daily? That seems like a huge consumption of components.

 

[Varminterror]

@South Prairie Jim - I’m not sure whether my words weren’t clear or if you simply choose not to read what is written.

I do appreciate an individual’s right to scroll on by if they prefer to not read my posts, so if you don’t want to read my posts, don’t. But it’s frustrating when folks who choose to not read rather choose to exercise their right to criticize - especially asking questions in such a rude manner when the answer they seek is written in the text they chose to skip over.

For those familiar with PRS, this simply isn’t possible, let alone sensible, as we might run 250-300 rounds just in zeroing and confirming velocity for and subsequently shooting a single 2 day match.

To spell this out more clearly since I obviously wasn’t clear enough for your interest in the first pass: A 2 day match will be 200-275 rounds, preparation for which typically includes confirming zero and velocity, and confirming the load remains in the node, good for another 10-50 rounds. So it’s quite common to put 250-300 rounds, or more, through a PRS rifle between cleanings.

... 250-300 rounds as opposed to the 50-100 rounds suggested by my buddy’s smith, who criticized the condition of his bore, himself neglecting the context of its purpose...

Since you asked not for 4 paragraphs, and being considerate to your request, and worrying that you may not choose to count the quoted section as an independent paragraph among this new content, I’m adding this 5th paragraph - which is probably not serving any utility - to be respectful of your rather curt request. Hopefully the 4 paragraphs of explication above explain what you chose to ignore in the 8 words of the original post.

 

[Laphroaig]

The problem with bore scopes is that you see things that most people don't need to, or shouldn't see. Like tool marks or a trace of copper fouling. So all of a sudden, a perfectly good shooting rifle suddenly becomes defective.

I'm starting to believe that cleaning often doesn't improve accuracy. At least in my rifles. Once every 250-300 rounds or at the end of the season is plenty. You can "read" your patches to determine where you are in the cleaning process. You don't need a borescope.

But the $50 Teslongs are inviting. Just beware of what you're going to see!

 

[JFrank]

@South Prairie Jim - I’m not sure whether my words weren’t clear or if you simply choose not to read what is written.

I do appreciate an individual’s right to scroll on by if they prefer to not read my posts, so if you don’t want to read my posts, don’t. But it’s frustrating when folks who choose to not read rather choose to exercise their right to criticize - especially asking questions in such a rude manner when the answer they seek is written in the text they chose to skip over.



To spell this out more clearly since I obviously wasn’t clear enough for your interest in the first pass: A 2 day match will be 200-275 rounds, preparation for which typically includes confirming zero and velocity, and confirming the load remains in the node, good for another 10-50 rounds. So it’s quite common to put 250-300 rounds, or more, through a PRS rifle between cleanings.

... 250-300 rounds as opposed to the 50-100 rounds suggested by my buddy’s smith, who criticized the condition of his bore, himself neglecting the context of its purpose...

Since you asked not for 4 paragraphs, and being considerate to your request, and worrying that you may not choose to count the quoted section as an independent paragraph among this new content, I’m adding this 5th paragraph - which is probably not serving any utility - to be respectful of your rather curt request. Hopefully the 4 paragraphs of explication above explain what you chose to ignore in the 8 words of the original post.

Too funny, you got me I must’ve cherry picked through the blather...
Your alright in my book
J

 

[JFrank]

The problem with bore scopes is that you see things that most people don't need to, or shouldn't see. Like tool marks or a trace of copper fouling. So all of a sudden, a perfectly good shooting rifle suddenly becomes defective.

I'm starting to believe that cleaning often doesn't improve accuracy. At least in my rifles. Once every 250-300 rounds or at the end of the season is plenty. You can "read" your patches to determine where you are in the cleaning process. You don't need a borescope.

But the $50 Teslongs are inviting. Just beware of what you're going to see!

Short range Benchrest guys are constantly cleaning and loading at a match , long range guys have pit duty so there’s no time for either during the match so most competitors clean afterwards, as far as bore scopes the Teslongs are great except as you indicate people tend to react negatively.

 

[d2wing]

The problem with bore scopes is that you see things that most people don't need to, or shouldn't see. Like tool marks or a trace of copper fouling. So all of a sudden, a perfectly good shooting rifle suddenly becomes defective.

I'm starting to believe that cleaning often doesn't improve accuracy. At least in my rifles. Once every 250-300 rounds or at the end of the season is plenty. You can "read" your patches to determine where you are in the cleaning process. You don't need a borescope.

But the $50 Teslongs are inviting. Just beware of what you're going to see!

I think it depends on the rifle and the degree of accuracy.

 

[Walkalong]

You can get clean patches and still have hard carbon laid down in the bore.

 

[Walkalong]

I think it depends on the rifle and the degree of accuracy.

Absolutely

 

[Jim Watson]

Back when an entry level borescope was $700, a guy brought his to a match. He would run it through your barrel for a fee. The main effect was to scare people into thinking their barrel was shot out... immediately after shooting a good score.