Gunsmithing I'm new to barrels and just got a borescope!

[JWG]

I can feel the cringe the title illicited, but it's also true. The beauty is, that I know I am ignorant, I know I do not know what I am looking at, and I'm curious and willing to learn. This is the first barrel I've borescoped, and am curious how it looks to someone who would know. My perception of what I'm seeing is captured in said video, right or wrong.
I'm happy to be educated.

 

[1moaoff]

Looks like a new AR Barrel

 

[JWG]

Looks like a new AR Barrel

Hmmm. How does it rate? I mean, is this pretty or just meh?

 

[Steel head]

Hmmm. How does it rate? I mean, is this pretty or just meh?

looks pretty nice.
Chamber appears to be slightly offset from the bore but my first Shilen was like that and it was an amazing barrel.

 

[JWG]

looks pretty nice.
Chamber appears to be slightly offset from the bore but my first Shilen was like that and it was an amazing barrel.

Offset in what way? It is a 5.56 chamber.

 

[Steel head]

Offset in what way? It is a 5.56 chamber.

look at where the lands start
Maybe it’s the way you move the camera but some appear longer than others.
that means the reamer was not perfectly square and/or concentric to the bore.

It’s not rare on cheaper barrels and factory barrels.
If your spending $700-800 on a barrel from a highly skilled and detail oriented smith then I’d be kinda miffed about it.

It’s definitely not a guarantee the barrel will not shoot well.

It takes time and expense to fixture up a barrel to less than a tenth of of the width of a human hair.
Time=$$$$$$


Shoot it.
That’s the real gauge of a barrel.

 

[Ledzep]

The other thing you'll see in hammer and button barrels is the lines the run perpendicular to the bore axis. On a cut (or buttoned for that matter) barrel that has been lapped, you'll just see smooth lap marks that run in the same axis of the bore.

Unless there's a giant goof in the rifling somewhere, I mostly don't even worry about the length of the barrel. Most of what I'm looking at is from the neck forward about 6-8" to monitor fire cracking, throat wear, etc...

On a new barrel, the same probably applies, look for jagged/uneven machining in the throat, rings in the chamber, and in the case of AR's, gas port location (looking for burs mostly).

Looks like a good factory AR-15 barrel.

ETA: I'll echo Steel Head insomuch as I wouldn't get caught up with anything you see unless the barrel doesn't shoot (or it's just outright fugly). Proof is in the pudding. I've scoped a factory rifle that had shallow rifling running all the way back to the neck on one side of the free bore and it still (somehow) hammered.

 

[1moaoff]

Shoot first then judge your barrel.

 

[Steel head]

Shoot first then judge your barrel.

Really good advice!

I bought a bore scope to show me how little a visual inspection means compared to actual results.

Andcto watch out for carbon rings.

 

[JWG]

I see it now. Does this mean the chamber is not concentric, or will this affect barrel life or bullet stability through a suppressor? The barrel is hammer forged, cut chamber.

 

[Ledzep]

Will not affect barrel life, stability, nor exit through a suppressor. Only has the potential to degrade accuracy. It's not the worst thing I've ever seen. 100% would test fire it first because it might not matter at all.

 

[Steel head]

I see it now. Does this mean the chamber is not concentric, or will this affect barrel life or bullet stability through a suppressor? The barrel is hammer forged, cut chamber.

Odds are if you never saw it you’d be a happier person.
Millions of barrels look like that yet last and shoot well.

Bore scopes are a great example of ignorance is bliss!

 

[Praeger]

Also remember the lens on your borescope is likely a wide angle bouncing off a not-perfectly-flat mirror. You can check it by laying the scope on the length of a ruler's scale and see if the measurement subtension hash marks look perpendicular. Easy for optical illusions to be introduced to the image.

Find a factory Remington, Savage, or Ruger barrel and compare it to your barrel. You'll feel better.

 

[JWG]

Also remember the lens on your borescope is likely a wide angle bouncing off a not-perfectly-flat mirror. You can check it by laying the scope on the length of a ruler's scale and see if the measurement subtension hash marks look perpendicular. Easy for optical illusions to be introduced to the image.

Find a factory Remington, Savage, or Ruger barrel and compare it to your barrel. You'll feel better.

Understood, but not all lands showed length difference. Image is true to reality as best I can tell.

 

[Brux]

Which borescope?

 

[BLKWLFK9]

The title to this thread is the phrase that makes gunsmiths cringe.

 

[Steel head]

The title to this thread is the phrase that makes gunsmiths cringe.

I bore scoped my new brux I got from keystone

It looked as beautiful inside as it actually shoots.

 

[JWG]

Which borescope?

Just a cheap $50 one off Amazon

 

[SupressYourself]

That barrel looks about 100 times better than my 6 Creed Dracos did when it was new. But it shoots...

 

[Maxduty]

My first piece of advice to a new bore scope owner is sell your bore scope. Shoot it and enjoy the barrel. Don't get overly concerned with seeing everything going on.

 

[Bradu]

My first piece of advice to a new bore scope owner is sell your bore scope. Shoot it and enjoy the barrel. Don't get overly concerned with seeing everything going on.

They are a nice tool if used correctly for issues like dealing with a carbon ring. I looked at my other barrels out of curiosity buy wouldn't sweat what it looks like if it shoots well.

 

[JWG]

Well, I just scoped a BCM BFH (circa 2012?). Beautiful barrel. Also the leade was cut WAY off center. Much moreso. I have shot this barrel suppressed/unsuppressed, and it's fine. Doing a much less worry now.

 

[JWG]

I see it now. Does this mean the chamber is not concentric, or will this affect barrel life or bullet stability through a suppressor? The barrel is hammer forged, cut chamber.

Question...how "clean" should one expect the leade to be? Is this looking good, or rough?

 

[acudaowner]

be more fun to repeat that video after you fire a few thousand rounds a before and after type of deal .

 

[JWG]

be more fun to repeat that video after you fire a few thousand rounds a before and after type of deal .

This is a similar barrel, except 14.5 middy, after about 1K rounds.

 

[goneballistic]

looks pretty nice.
Chamber appears to be slightly offset from the bore but my first Shilen was like that and it was an amazing barrel.

What did you see that made you think the chamber was offset? Looked pretty normal to me, but I'm an idiot, so there's that.

What an I looking for?

OP the barrel looks great, very smooth and well finished from what I can see