Help me interpret this borescope video: fire cracking, carbon ring, throat erosion

[new2mud]

Next time get a 3 groove Nitrided barrel and you'll see at least 3000 rounds.

There is a reason ALL military gun bbls are nitrided.

Yes! I want a nitrided barrel next. Who offers them and/or offers nitriding services for individual barrels?

Wait...no...I'm trying to extend the life of this barrel. hmm....

 

[Creedmoor shooter]

I just dealt with a carbon ring in my 6.5. I bought the teslong horse scope and that's how I figured out why my rifle was shooting like crap. You definitely have some fire cracking there. I wouldnt say you have a carbon ring yet. You definitely have some carbon build up at the end of the case mouth but it's not into the free bore yet. Mine went into the freebore and actually all the way to the rifling. Couldnt figure out for the life of me how much oal to the lands got shorter lol. I'd definitely remove that carbon though. I used jb bore paste and a few hours of elbow grease.

 

[David Emerson]

Barrel is a stainless 6.5 PRC w/ 0.188 freebore right at 600 rounds through it. Mostly handloads of 147 ELD-M and Berger 156 EOL with N565 powder until the recent (last 50 rounds) switch to H1000.



My questions:

1. How bad is this firecracking?
2. Do you see evidence of the dreaded carbon ring?
3. Based on what appears to be the distinct ring where the chamber cutter ended and the lands are tapered, how much throat erosion is apparent?

First--it's your fault--this forum is what informed me about the low-cost Teslong borescope, and kids just got me one for my birthday—awesome.
And yes, I realize that every newbie with a borescope is now a barrel hypocondriac!

But it's cool, and informative to know what's going on inside the bore.

And now videos like this enable folks like me to learn from the experienced smiths and folks like you on this forum that have more years looking down barrels. (From the chamber end)

From what I have seen your lands are not moving forward yet. The erosion at the end of the chamber is nothing to worry about. I have seen far far worse that still shoot well. Lots of life left. When you start to see voids a good session of JB bore paste is in order but only do the area that is fire cracked with some erosion

 

[RWE]

Hello new2mud, I have to say I laughed out loud reading your post and this thread. I don't even have one (yet) and can already see the worry I will cause myself (which model do you have? Is it iPhone/iPad compatible?).

I want one so that I can investigate a 30-06 I have. It went to heck a fewe years ago, slowly. It surely has less than 1500 rounds through it, more like less than 1000 rounds to be honest. I keep better track of things now. Last fall I cleaned it correctly and thoroughly, even used some KG2, and it is shooting sub MOA again! Its like magic really. Maybe it was a carbon ring? Copper fouling? But it is clean now! So, the .280/.280AI project is shelved for now, or did I decide on making it a 6.5-06, or....

I would also like to use it on my other rifles - to keep tabs on carbon build up to spare myself the agony of what the '06 put me through. That said, the fire cracking might be more than I can bare!

 

[TK50]

From the looks of the carbon ring in the neck portion of the chamber you are trimming your brass a little on the short side for the chamber you have. You will have much less carbon buildup in that area if you don't trim them as much as you are now. There is a fine line though because you don't want them to get too long otherwise you will run into pressure problems.

 

[bengineer]

Look in any used 243. That will cool your jets.
I have one with 3" of alligator skin cracking in the barrel that still hits prairie dogs at distance.

 

[new2mud]

s

Hello new2mud, I have to say I laughed out loud reading your post and this thread. I don't even have one (yet) and can already see the worry I will cause myself (which model do you have? Is it iPhone/iPad compatible?).

I want one so that I can investigate a 30-06 I have. It went to heck a fewe years ago, slowly. It surely has less than 1500 rounds through it, more like less than 1000 rounds to be honest. I keep better track of things now. Last fall I cleaned it correctly and thoroughly, even used some KG2, and it is shooting sub MOA again! Its like magic really. Maybe it was a carbon ring? Copper fouling? But it is clean now! So, the .280/.280AI project is shelved for now, or did I decide on making it a 6.5-06, or....

I would also like to use it on my other rifles - to keep tabs on carbon build up to spare myself the agony of what the '06 put me through. That said, the fire cracking might be more than I can bare!

Haha. You just have to approach it as a diagnostic tool and not strive for perfection, as many on here have noted.

I got the $50 version that is for PC/Mac/Android (USB/micro USB cable end) so I can plug it into a laptop and have the nice large display.

I, too, am a huge fan of the KG line. The copper solvent is amazing, esp for not being ammonia-based.

 

[new2mud]

From the looks of the carbon ring in the neck portion of the chamber you are trimming your brass a little on the short side for the chamber you have. You will have much less carbon buildup in that area if you don't trim them as much as you are now. There is a fine line though because you don't want them to get too long otherwise you will run into pressure problems.

Wow, you're good. Yes, my brass has been getting trimmed down to 2.005", which is shorter than the 2.015" spec.

 

[new2mud]

Thank you all for your helpful replies and anecdotes. I learned a lot through this thread, (including that .243 barrels are crack-heads) and that fire cracking isn't something to fear.

I've learned that the carbon ring will likely show up where the freebore ends and fire cracking begins, and to keep an eye out for that area for carbon buildup.

 

[Betarider]

If that little bit of wear looks scary wait till you see a copper fouled barrel
You can now load those long bullets and get another 600