First borescope experience - 28 Nosler carbon ring

[Harvey_NW]

Wow. All the videos were right, you really have no idea what's going on in there until you stick a camera in. For a $60 borescope off Amazon, I'm extremely impressed. Android app is super simple, just download and plug it in.

https://www.amazon.com/gp/aw/d/B07TTQF24F?psc=1&ref=ppx_pop_mob_b_asin_title

Peeked into the bore of my slightly problematic 28 Nosler that has an estimated 200 rounds on it and gave me a little pressure spike at a low charge doing some load testing. At first it was hard to distinguish what I was actually looking at, initially it looked like some pretty nasty tooling marks in the neck area (turned out to be carbon), and it was hard to identify the end of the neck area and taper to freebore. So I chambered a case and got a better idea.


Still wasn't really sure what I was looking at, so I decided to start cleaning. I used boretech eliminator on a soaked patch wrapped around nylon brushes in 284 for the barrel, and a 30 cal brush on a short rod chucked up in a drill for the neck area. It started to show its ugly self..


More boretech, more scrub. Eventually I got about 95% of it busted out and could see what I was looking at. I'll have to stay on top of it.


Something I noticed, the boretech eliminator seemed to hammer the carbon, the barrel came clean after about 15-20 initial passes, but it didn't even touch the copper. I grabbed the Sweets and gave it another 20 strokes with a patch around a brush, and let it sit for a couple minutes before I dry patched it out and hit it with CLP to neutralize it, didn't seem to have any effect either.


Was doing all this outside and it started to rain, so I called it quits. That picture was probably a couple inches in from the muzzle end, the copper fouling was the worst in the first 1/3 of the barrel from the muzzle, and the middle to chamber area it was almost non existent.

So what are you guys doing to get the copper out? I thought Sweetser was super aggressive, or did I not use enough or wait long enough?

 

[atmat]

Wait, y’all are cleaning your rifles?

 

[Harvey_NW]

Wait, y’all are cleaning your rifles?

280ai, not too worried about it. 28 Nos, absolutely. A 200fps velocity spike and a nearly scorched pair of shorts will encourage you to look down in there!

 

[DangerRanger]

28 nosler is another beast. Hornady on their podcast talks about the differences they see in pressure readings from cleaning intervals between relaxed and overbore cartridges.

2 anecdotes they have given are a 6arc barrel they put 2k rounds down without cleaning and no pressure changes and a prc barrel that pressure spiked radically at 150 rounds without cleaning.

The no cleaning thing is cool on 308s,223s etc but you get into monster overbore cartridges like a 28 nosler and it seems like you better pay close attention to your velocity readings or pressure signs.

 

[wildcat33]

Wow. All the videos were right, you really have no idea what's going on in there until you stick a camera in. For a $60 borescope off Amazon, I'm extremely impressed. Android app is super simple, just download and plug it in.

https://www.amazon.com/gp/aw/d/B07TTQF24F?psc=1&ref=ppx_pop_mob_b_asin_title

Peeked into the bore of my slightly problematic 28 Nosler that has an estimated 200 rounds on it and gave me a little pressure spike at a low charge doing some load testing. At first it was hard to distinguish what I was actually looking at, initially it looked like some pretty nasty tooling marks in the neck area (turned out to be carbon), and it was hard to identify the end of the neck area and taper to freebore. So I chambered a case and got a better idea.
View attachment 551090View attachment 551091

Still wasn't really sure what I was looking at, so I decided to start cleaning. I used boretech eliminator on a soaked patch wrapped around nylon brushes in 284 for the barrel, and a 30 cal brush on a short rod chucked up in a drill for the neck area. It started to show its ugly self..
View attachment 551092

More boretech, more scrub. Eventually I got about 95% of it busted out and could see what I was looking at. I'll have to stay on top of it.
View attachment 551094

Something I noticed, the boretech eliminator seemed to hammer the carbon, the barrel came clean after about 15-20 initial passes, but it didn't even touch the copper. I grabbed the Sweets and gave it another 20 strokes with a patch around a brush, and let it sit for a couple minutes before I dry patched it out and hit it with CLP to neutralize it, didn't seem to have any effect either.
View attachment 551095

Was doing all this outside and it started to rain, so I called it quits. That picture was probably a couple inches in from the muzzle end, the copper fouling was the worst in the first 1/3 of the barrel from the muzzle, and the middle to chamber area it was almost non existent.

So what are you guys doing to get the copper out? I thought Sweetser was super aggressive, or did I not use enough or wait long enough?

Wipe out works good on copper. Pre treat with the accelerator for extra stubborn fouling.

 

[DangerRanger]

So,to your original question to clean my 300prc I used c4 for the carbon in the throat (and everywhere else) and then montana extreme copper killer for the copper.

Outdoors, or open air, it’s brutal

 

[wapitibob]

montana copper killer for carbon
clr for carbon

 

[Axlrod]

I had a 28 Nosler that I had to use a piece of 2x4 to get the bolt open after about 50 rounds. Bore scope showed lots of carbon. With my 30 Nosler I have now, I run a patch of boretech elim. through it at the range. Then finish dry patching when I get home. I do this every time I shoot it, if it's 3 rounds or 30.
I have a 223 that has 5000+ rounds without ever running a patch down it. Seems to be a big difference between 23 grains of H4895 and 80+ grains of N570 & H1000.

 

[Gingerman]

I've gone to minimal "mechanical" methods of cleaning and adopted the "Chemical & Time" method. Copper is weird in that it will resist follow on coats of solvent unless cleaned off/out with alcohol between solvent applications. I shoot Savage barrels. I know how to clean copper!

1. Shooter's Choice or Wipeout foam. Apply and then reapply/foam within 10 mins. Foam on foam makes the second application stay foamy longer. Let the second foaming sit overnight or 4-6hrs.

2. After the soak, run a dry patch to look at all the pretty colors and gunk. Follow up with patches soaked in alcohol till they come out clean(ish) Inspect with borescope. If there is remaining copper, next step.

3. Run a bronze brush soaked in alcohol and do 10-15 passes. Follow up with alcohol soaked patches. Inspect with bore scope. If copper still present, next step. (One should only see some specks of copper t this point)

4. Short stroke/long stroke a copper solvent in the bore. Let sit 1/2 hour. Follow with alcohol soaked patches.

This procedure should either remove or soften the carbon ring. If not, I will agree to a larger caliber size brush on a drill, being careful not to extend the brush into the throat. Borescope down the bore looking at your work helps.

Also, take note how much clearance you have between the case mouth and chamber wall. You might just stop trimming brass.

 

[Forestryguy]

Question from a semi newbie. I can see the issue with carbon build up, especially a ring at the bore, causing pressure spikes. Wouldn't you want to leave the copper to fill in the tooling marks and imperfections? Or are you getting so much copper residue that is completely filling the lands and grooves?

Just yesterday I was thinking about maybe a 27 Nosler just for hunting at longer ranges than we do in the East.

 

[Gingerman]

Question from a semi newbie. I can see the issue with carbon build up, especially a ring at the bore, causing pressure spikes. Wouldn't you want to leave the copper to fill in the tooling marks and imperfections? Or are you getting so much copper residue that is completely filling the lands and grooves?

Just yesterday I was thinking about maybe a 27 Nosler just for hunting at longer ranges than we do in the East.

I would call that maintaining barrel equilibrium. If that was the only copper left in the bore. I've never been that lucky and always have to clean the build up piles out, thus eliminating all copper.

 

[Tmac]

Have had real good results with KG-12 copper remover. No ammonia, no stink, no chemical damage to rifle barrel. It’s very active against copper as test results bore out. Someplace a guy tried about 10 different solvents, it did the best. Been a few years so forgot where the test was done.

 

[6.5x284]

I use the Boretech C4 for carbon and Boretech CU+2 for copper. I've ditched Montana Extreme since running Cu+2. But I agree, you can't just run eliminator. I generally go with C4 for Carbon first, CU+2 for Copper, then C4 for any carbon under the copper for my last patches. With a 6.5 SAUM I clean every couple hundred rounds. Other stuff I rarely clean or after a dirty match.

 

[Formidilosus]

Seems to be a big difference between 23 grains of H4895 and 80+ grains of N570 & H1000.

There is a difference, and maybe is matters... However @Ryan Avery and I, as well as couple dozen others I know all shoot larger magnums without cleaning, do not have pressure issues, and get the same barrel life. That’s on most/all brands of barrels, and with cartridges from 6mm with 65gr of powder to 300 and 338’s with more than 100gr of powder.


Bore scopes are another distraction path for people to go down that has nothing to do with shooting or hitting things.

Or are you getting so much copper residue that is completely filling the lands and grooves?

No. No matter how much you shoot them, copper nor carbon will fill the lands of grooves. By just measuring the bore diameter, you can’t tell whether a barrel has 50 or 100 rounds on it, or 10,000.

 

[Harvey_NW]

There is a difference, and maybe is matters... However @Ryan Avery and I, as well as couple dozen others I know all shoot larger magnums without cleaning, do not have pressure issues, and get the same barrel life. That’s on most/all brands of barrels, and with cartridges from 6mm with 65gr of powder to 300 and 338’s with more than 100gr of powder.

How overbore are those magnums though, or what am I missing here? Seems to be prevalent in 28 Nosler and 6.5 PRC. As quoted already even the Hornady guys talked about popping primers after 150 rounds in PRC testing.

 

[hicountry1]

I use boretech eliminator for copper.

I run a few soaked patches thru, then hang the rifle upside down, usually put a towel under the muzzle, and prop the rifle against my loading bench, so it vertical.

I hang overnight. The green on the towel tells the tail of how much copper came out. Patching the next day also shows if it needs to be repeated.

I've noticed once the rifle is broken in, one hanging session does the trick. I've had new custom bbls take several days of patch and hang during the break in process.

Once it gets to only an overnight hang, the bbl is broken in.

Even if I don't need to hang a rifle overnight, I'll let the eliminator soak hanging upside down for a few hrs.

PS...I have prongs on my bench so that the rifle can't be accidentally knocked over.

Works for me anyway, YMMV....

 

[Formidilosus]

How overbore are those magnums though, or what am I missing here? Seems to be prevalent in 28 Nosler and 6.5 PRC.

100-120 grains of powder in 30 and 338 cals… pretty “overbore”. 68gr in a 6mm, yeah. As for PRC’s, man I’ve shot and seen a bunch that are never cleaned.

As quoted already even the Hornady guys talked about popping primers after 150 rounds in PRC testing.

Yes, but they also ironically committed the very same mistake about “cleaning” that they warned people not to do in the group size testing- until fully testing something, don’t make assumptions on small, random samples that may or may not have anything to do with what you saw, or think you saw.

I can state with absolute certainty that factory 6.5PRC rifles can shoot factory 6.5PRC ammo and not blow primers or anything else.

 

[ID_Matt]

@Formidilosus Not cleaning in the big magnums, are you guys ever seeing the weird pressure spikes that people talk about? What is causing certain people to have them? Is it that they cleaned at some point and that encourages a carbon ring later on? Is it that they are burning too close to pressure from the beginning? I'd love to never clean my 7 saum, but it just seems after a few hundred rounds it starts to get the odd spikes and I am forced to clean.

 

[Formidilosus]

@Formidilosus Not cleaning in the big magnums, are you guys ever seeing the weird pressure spikes that people talk about? What is causing certain people to have them? Is it that they cleaned at some point and that encourages a carbon ring later on? Is it that they are burning too close to pressure from the beginning? I'd love to never clean my 7 saum, but it just seems after a few hundred rounds it starts to get the odd spikes and I am forced to clean.

I don’t know. I do know that I/we don’t chase the lands, don’t work up loads that are right on the bleeding edge when the barrel is new/clean, and in general do not use temperature sensitive powders.

If you do load work up with the bullet seated close to the lands “cause that where accuracy is”, and go until you see pressure signs- well First your already over pressure at that point generally, and then yeah I could see issues popping up as the throat got fouled. My answer to that is- don’t do that. With most of the bullets people are shooting now, seating depth has very, very little to do with group size.

I can say that myself, Ryan Avery, PNWGATOR, and several others on here alone, have none of the issues that people talk about. As in ever. I’ve shot a couple dozen 30 and 338 magnum barrels out, without ever putting anything but bullets through the bore with no issues. I’ve seen many, many others done the same.


@PNWGATOR how many rounds do you have on your current 6.5 PRC barrel?

 

[PNWGATOR]

500’ish (?), but I don’t have the exact round count in front of me.

I‘ve never run a brush through it.