Home Forums Hunting & Shooting Ask The Gunwriters What a bore scope can show you

Rather than have this get lost in the two other bore scope threads, I'll post this here.

This is a project gun I'm rehabbing....an Interarms Mark X in 30-06. I'm a sucker for an orphan gun and bought it off the used rack at a local shop.The barrel was full of goo and obviously hadn't been shot much and cleaned less, if at all. Here's what the borescope shows. Borescope used here is a 26" rigid Teslong with the red angled mirror.

#1: Chamber is to your left...you can still see the bluing in the chamber. And then there's this shiny area on the right.


#2: Going further upstream, here we are dead in the middle of the shiny band. Again, the chamber is to your left.


#3: Wading upstream a bit more, the shiny band is on your left and a nice appearing section appears ahead of it to the right...bluing reappears. Note no rifling.

Somebody ream some freebore so they could seat longer bullets out of the powder space?

If they did that it would also push the leade deeper and you'd see the blueing on the rifling would also have been removed.

Al, somebody reaming the neck area to a bigger diameter?

The shiny band is the shoulder area of the chamber. I'm going to test fire a few tomorrow and see what the case shoulder looks like.

Good shootin' -Al

Al, is this a test? Knowing your talent this one is a ground ball for you. Guessing you will set the barrel back and recut the chamber.

While you are at it you will probably blueprint the action, bush the firing pin hole, and install a Timney trigger - just because you can’t help yourself…

No...not a test. Just thought it might spark more people to think about why the shoulder area has a machined finish when the chamber and neck still shows intact bluing.

The ground ball ended up a swing and a miss.

Good shootin' -Al

Well maybe that one had a bit of a tight headspace issue and had to be polished a bit. ?
Always interested in your work sir.
F01

These barrels are hammer forged. That process forms the chamber along with the barrel internals as the barrel material is literally hammered into shape over a carbide mandrel. The barrels are then blued and fitted to the action. Then a pull style reamer that contacts the shoulder area of the chamber is used to set the final headspace. That's why only the shoulder area of this chamber appears as a machined finish.

Many other mfgs use the same process of course but blue the barreld actions together after headspace is set...which is why you don't see the shoulder area of the chamber in the 'as machined' finish.

As always, understanding a process can help us make sense of what we see. This one made me go back to basics when I first saw it.

Good shootin' -Al

Pretty good deduction skills! -Al

🤣🤣🤣
Granddaughter has a bad habit of swinging at really low pitches. She got suckered in to swinging and missed, her coach said to her "okay Tiger, now that you got that one out of your system". I almost fell out of my chair laughing. I returned the favor by yelling at the coach "Ya. even Helen Keller wouldn't have swung at that pitch". 😛

The surface in that image looked flat to me, not angled. I thought maybe someone ran a neck reamer in the chamber but the neck/throat junction didn't look right.

The stripped bolt closed nicely on the 'Go' gauge so off to the range I went. With a max. load of IMR4064 (ok...a bit more than max ), my 150 flat based bullets jammed hard into the lands and a bit of light lube on the cases, it whapped the cases out nicely. Extraction was effortless and the pin strike was well centered on the primers. Chamber neck diameter checks at .343 and the back end of the chamber is nice and snug. Neck runout on the fired cases is right at .001. I had also shortened the barrel 2" and recrowned it and the powder pattern on the muzzle is nice and symetrical.

Good shootin' -Al

Thanks Al. I find your post educational and insightful - keep 'em coming!

Thank you sir. Shortening the barrel on the Mark X pains me a little as they are one of the few who offered a full 24” home for the old ‘06. I’m an unabashed fan of longer barrels and shorter barrels. I guess I’m biased against the 22” length. No real good reasons just my own likes. I really have enjoyed the bore scope threads.
Best regards,
F01

Yes...I would have rather left it at 24" and just touched up the factory crown. Borescopeing showed some issues that made pulling it back 2" a better approach.

Good shootin' -Al

Thanks...appreciate it. -Al

Had no idea the chamber was also hammer forged! Thanks for that information Al.

Not all mfgs. include the partial chamber in the process. Some pull or push the carbide mandrel (that has a short section of rifling on it) along the length of the barrel as it's hammered. Then the chamber is done. Lots of ways for mfgs to accomplish this. If you ever get the chance to see...and hear...the hammer forging process, it's pretty amazing.

Yep!

When Bill Ruger finally decided that the company needed to start making their own barrels around 1990, he did a lot of research and decided on hammer-forging, buying machinery from a company in Germany. The consistency of Ruger barrels immediately improved considerably, but continued to improve: One of Ruger's production honchos told me this was because even though hammer-forging sounds like an "automatic" process, it still requires some experience from the operator(s) for the best results.

All of which is partly why Ruger American Rifles immediately acquired a reputation for grouping very well: RARs appeared in 2012....

Wow, what a safe queen you found there, still blued inside? Not the prettiest final ream, but the bullets won't know that. Good luck, Al, and thanks for the lesson.

The remaining question this inspires to me wonder is: "does that finish affect anything (to practical effect")? I would presume "yes" if one were chasing the finest causes of variation, otherwise it's a "no" to most users. Thanks for posting.

As bad as the bore scope makes the shoulder area finish appear, the shoulders on the fired cases look fine. Which was one of the reasons I leaned on the test fire rounds pretty hard...to make sure the case shoulder area blew out hard against the chamber.

I might still give the shoulder area a little touch up. 🤔 But sometimes, the enemy of 'good' is 'better'.

Good shootin' -Al

Interesting. Yesterday I cleaned my sons Winchester 243. It’s an older one perhaps early 80’s maybe 70’s. I bought it with a Japanese tasco for 250 bucks several years ago. Gun has seen some rounds and use. Decided to really clean the barrel. About 3 days of soaking and re soaking. Then a jb clean. The borescope showed me pretty heavy X tooling marks in the shoulder area. Brass comes out fine and the gun shot 3/4 moa nice and triangular groups when I zeroed it a couple years ago with a load I had for another 243. I was very happy with that.

A friend manages a gun store and offers free bore scoping to customers.

He gets a LOT of guys wanting to trade in their rifles after seeing inside.

My friend tells his customers that the rifle may shoot fine anyway, but many customers want to ditch their rifle because they think it will SOON start shooting badly.

Alternatively, some customers may be bothered knowing that their "baby" has a fault - like seeing a beautiful woman and finding out she has a venereal disease.

However, many bores with "severe" faults like a piece of rifling completely missing or a barrel bulge visible only on the inside shoot surprisingly well, and others need only cleaning back to bare metal and re-fouling...!

/John

You mean like:

"Keep fixin' it until it's broke"?

Question: which Teslong are you all using? I see models ranging from $49 to $215. It would seem the simple 45" flexible scope would be the most practical and work on about anything.

I've got the cheapest flexible one. I think, Al mentioned he had a rigid model. I love the flexible one - great pictures. Just plug it into a lap top and have fun. Really helped getting down to bare steel before applying Dyna-tek Borecoat and also, polishing the throat on a new rifle. Seeing the tool marks before and after was pretty dramatic.

Thanks.

I have a Remington 700 .30-06 with a 24” barrel as does my Model 70 Super Grade. Very interesting post btw.

One of the smarter things Ruger ever did. Good barrels heal many sins

I bought a used Hawkeye some years ago, and it was an "eye opening experience" to see the varieties of bore condition in different rifles. I bought a Ruger No 1 in 6mm Remington from 1976, and the rifling looks like the Ghost of Harry Pope and Krieger collaborated, taking a year to make it. An earlier #1 in the same chambering looked in terrific condition on the outside. The bore was burned to a crisp for about a foot in front of the chamber.

A borescope is a great tool. Might have to get a Teslong, just for the picture taking ability.

Teslong is a pretty good thing to have @ a gunshow. I don't worry much about it when buying from brick and mortar. If there's an issue for the most part I've never had a problem coming to a mutually beneficial arrangement. A "gun show guy" however may be much more difficult to track down so a little more due diligence isn't a bad thing.

When talking about about throats and throat angles, it's kind of hard to visualize. This morning, I was bore scoping a new barrel for this season and thought it gave a pretty good representation of what we're talking about. Put the Hawkeye away and put the Teslong in for ease of grabbing pics.

From rt to lt: The chamber neck is to the right. The narrow band to the left after that is the 45 degree transitional angle from the end of the neck to the throat. Moving left, now we're into one of the lands. The throat angle is clearly visible on the upper edge of the land as it transitions from throat diameter (.3085 in this case) to land diameter (.3000). More correctly, we're looking at the land height relative to the throat.

For what it's worth, for anyone interested. -Al

Great picture Al. Isn't the land diameter 0.300 in this case though?

Yes...corrected it. -Al

👍
Thought I might need another cup of coffee for a minute there.

Obviously, I sure did!

Those things do take nice pics.

Anybody have a recommendation for a phone app other than Smart Endoscope? I hadn't used it on the phone I got last fall until yesterday and below is what it's doing. Other OTG/USB camera apps work but the few I've tried haven't been all that great. Smart Endoscope app still displays as it should on my old phone and a laptop also displays fine so I don't think there's anything "wrong" with any one component. For whatever reason the Smart Endoscope app and my Samsung phone don't speak the same language. Most of the time I use the laptop for the bigger image but there are times it's handy to use the phone without having to track down my old one.

I have a Samsung Galaxy A13 phone and it is showing images the same as your phone. My old phone, Samsung J7 Prime, worked perfectly. Laptop and desktop work perfectly, but the A13 will not sync the pictures properly. I called Teslong and the tech was very helpful but she could never tell me what was happening or how to correct it. She explained that the phone had to support OTG/USB. She could never tell me how to determine whether my phone supported OTG/USB or not. Could not tell me how to turn the feature on or off. So, to make a long story short, if you ever find out how to correct this problem would you please post it or PM me. Thanks, Mpickle

Mine is the Galaxy A14 and OTG is automatically on. I don't think there's a way to turn it off. If you want to test if your OTG is working, go to the Play Store and get another OTG camera app and try it with the Teslong. I bet it works. Just something about the SE app and the Galaxy that doesn't jive. Or even plug a flash drive into the adapter and see if it shows up in your files to test if it's working.

Sorry for the hijack, Al.

Scoped the bore on my new Remarms Rem 700 Long Range 300 Win Mag 5R.I haven't got to shoot it yet,but it looks good to me.

If I had read this yesterday, I would have expected photos of someone’s colonoscophy, but it’s 2 April and it’s Al posting so I knew it would be good stuff!

We truly live in a golden age when we can get a chronograph for ~$500 and a borescope for $200 when these just a number of years ago were beyond the reach of the average sportsman.

And even greater than that is the access to just about any expert at any level. For us, that’s folks like Al, Mule Deer, Scenarshooter, Eric Cortina, and George Gardner just to name a few.

We are truly blessed.

I wonder if you can save some $$$$ and do your own colonoscopy?

Ha! The borescopes I've used have all come with a warning not to "insert" them into any human orifice. (Which reminds me of the warning that came with our first cordless phone--not cell phone--many years ago, which came with a warning not to use the cradle as an ashtray....)

A good bore scope can show you a lot of stuff that you can't do a damn thing about!

Which kind of polyps are you talking about?

Borescope streaming to the big-screen? Check

Ex-Lax? Check

Air Compressor? Check

You first.

Well, I have met a lot of people that walk around with their heads up their arses-----so no need for a bore scope.

Call it a Birds Eye View!

Hip

This thread sure went in a "direction" I never expected!

because i have had a bore scope a long time and my friend Greg the machinist does too we both have looked at even new barrels that have not been shot yet . my question for the guys that use their bore scopes has anyone else check out new barrels too ? i have done some very expensive barrels that looked great but did not shot that good sometimes ,i also also have checked out some new cheap rifles like Savage barrels they look rough inside barrel channel but they shoot great ? another friend brought a very expensive rifle from North Dakota and his rifle could hardly shoot an 1 1/2 inch group at 100 yards, i purchased the same size cartridge in a cheap Savage both were 300 WSM and with the same ammo mine shot 3/4 inch at 100 yards . we looked thru both barrels with my bore scope his looked very nice my Savage barrel looked rough but it sure shot better. so sometimes ya the bore scope shows how well the channel looks but doesn`t always tell you how well the barrel will shoot. greg the machinist also has done some complicated measuring and using his bore scope to checked out new barrels that have come from barrel manufactures he now only uses two different brand barrels for himself but if someone brings in a different brand barrel he will install that barrel for them. i only use the barrels he recommends now too and i have had some great accurate barrels that Greg has done the machining on and installed. Pete53 > and those Savage rifles are a real mystery on how well those cheap rifles shoot right out of the box ???? as are the new cheap Ruger rifles ?????

When new barrels hit my door, they get bore scoped as soon as possible. -Al

Picked up a set of mirrors for my Telsong for $15.They give you a lot better view than the ones that came with the unit,especially when your looking at the larger bores.

For the most part. A bore scope won't even give you a suggestion as to whether a rifle will shoot good or not unless there are glaring issues

Here's the reason to bore scope a new barrel. This is a new one for this season.....the defect was about 1/4" back from where I wanted the muzzle to be.

Al,

Have seen things even worse in factory barrels. Probably mentioned one long ago in one of these threads: A major manufacturer's .300 Winchester Magnum barrel that had the lands totally missing about 1-1/2" from the the muzzle, probably due to reamer malfunction. The rifle wouldn't group better than 2" at 100 with any ammo until it was shortened enough to remove that "gap," and recrowned.

Those are great view of the canted side of the rifling on a 5R barrel. Hope it shoots well for you.

Good shootin' -Al

I bought a borescope last winter for curiosity Sake. I have a barrel my brother wore out on his benchrest rifle. It looks like a bad gravel road after cleaning. It shoots 5 into less than half inch with 80 grainers.
Yesterday I loaded up 5 105 barts bullets just to see how it shot. The group with cold bore was .365 and without cold bore the 4 shots were .185.
It’s shoots better than the nice looking barrels. Kinda funny after looking at the bore. It’s a 6 br by the way. Edk

Yes....bad looking doesn't necessarily mean bad shooting. All I expect either borescope to do is:

(1) Identify a significant defect in a barrel
(2) Qualify my cleaning process
(3) Help monitor the crowns condition

Good shootin' -Al

friend purchased a new Remington 700 and came over to show me this barrel was threaded fine but the rifle had never been chambered it was flat in the back. on the barrel and yes Remington chambered his rifle.

What do you expect from a new owner...perfection??

There`s a learning curve ya know.

That's a good one! I like a flat tenon on a 700 (no bolt nose counterbore) for several reasons. But they do have chambers in there! -Al

Wonder if it had the proof stamps? 😁

Finally made it to the range this morning to test out my new Remarms 700 Long Range 300 Win Mag 5R.Looks like she's going to be a good shooter.It came with the Timney non-adjustable trigger set at about 3.5lbs.The trigger is not too bad,but I usually run about a 2.5lb trigger.I only ran 12 rounds through it with two different loads.I ran a wet patch with Sta-Bil CLP,followed by a couple of dry patches after each shot.The barrel looks almost copper free throughout.I think I may have read the 5R rifling usually aren't bad about copper build up.Anyway here is nine of the first twelve shots I ran through it.

I have an older Hawkeye, which has been a very useful tool. I finally broke down and ordered a Teslong today. Being to take photos makes documenting barrel condition, quite easy.

And it’s just fun to look inside your barrels. The Teslong made that pretty affordable.