Carbon ring, necks trimmed too short?

[Waltjaevel]

Hi there,

I'm still in the early stages of reloading so every insight is greatly appreciated

I did the biggest mistake, looking through my bore with a borescope. The rifle shoots okay so no issues there, but I've been wondering about my neck lengths and tensions so I decided to take a look.

It's a factory tikka barrel with 1080 shots through. I don't clean my barrels religiously. Copper removal about twice or three times with BT (so after 300-400 rounds) and a bigger carbon removal at the same time. Couple of patches of Schletek 2-in-1 or BT Carbon remover after shooting and couple of clean patches before fouling shots. Used to use BT eliminator, but I don't mind some copper in the barrel. Patches or nylon brushes with Dewey bore guide.

Looking through borescope i see what i believe to be a carbon ring. Should I clean it off or is the build up still in the level where i shouldn't be too worried about?
I'm still uncertain of what's causing it. I use VV N555 with kind of mild loads (42gr, 6.5creedmoor SAKO LRP brass, 147 Hornady ELD-M) and the brass necks are fairly black after shots (see picture). Is this normal or does this have something to do with neck tensions / neck trim length?

I believe i trim my necks quite short while trying to keep them at the same length, could that be a big factor here?

The Carbon residues are fairly symmetrical (front pic is chamber side and end pic is barrel side), but there is one place where it's lacking carbon - what could cause this? (pic: asym)

So yeah, a lot of fairly elementary questions, but all the help are greatly appreciated!

 

[Seymour Fish]

Hi there,

I'm still in the early stages of reloading so every insight is greatly appreciated

I did the biggest mistake, looking through my bore with a borescope. The rifle shoots okay so no issues there, but I've been wondering about my neck lengths and tensions so I decided to take a look.

It's a factory tikka barrel with 1080 shots through. I don't clean my barrels religiously. Copper removal about twice or three times with BT (so after 300-400 rounds) and a bigger carbon removal at the same time. Couple of patches of Schletek 2-in-1 or BT Carbon remover after shooting and couple of clean patches before fouling shots. Used to use BT eliminator, but I don't mind some copper in the barrel. Patches or nylon brushes with Dewey bore guide.

Looking through borescope i see what i believe to be a carbon ring. Should I clean it off or is the build up still in the level where i shouldn't be too worried about?
I'm still uncertain of what's causing it. I use VV N555 with kind of mild loads (42gr, 6.5creedmoor SAKO LRP brass, 147 Hornady ELD-M) and the brass necks are fairly black after shots (see picture). Is this normal or does this have something to do with neck tensions / neck trim length?

I believe i trim my necks quite short while trying to keep them at the same length, could that be a big factor here?

The Carbon residues are fairly symmetrical (front pic is chamber side and end pic is barrel side), but there is one place where it's lacking carbon - what could cause this? (pic: asym)

So yeah, a lot of fairly elementary questions, but all the help are greatly appreciated!

Remove that carbon ring. Appears built up in layers, some of which flaking off. Consider increasing the charge

 

[CK1.0]

Those black necks can/might be caused by not removing all of the sizing lube from the cases.

As far as a carbon ring, those pics make it hard to tell exactly, but it looks like your overall chamber could use a cleaning. I, like most, tend to only see the rings form right up against the "shelf" before where the freebore and lands start.

IMO necks being too short isn't the huge deal some think it is... I've been shooting some Lapua cases that started out as 22-250Rem that I turned into 6CM cases with short necks (avg ~1.890") and after nearly 20 firings they are still barely SAAMI minimum (1.910")... and they haven't caused me any problems.

Here's a before and after of what I usually see:

 

[Waltjaevel]

Remove that carbon ring. Appears built up in layers, some of which flaking off. Consider increasing the charge

Soaked it in C4, and brushed with nylon brush. Got quite big carbon flakes out.

I have had the same idea with increasing the charge. I suppose I have to change the powder because N555 is filling up the cases quite well and I can't load them longer to fit the mags

 

[Seymour Fish]

Soaked it in C4, and brushed with nylon brush. Got quite big carbon flakes out.

I have had the same idea with increasing the charge. I suppose I have to change the powder because N555 is filling up the cases quite well and I can't load them longer to fit the mags

Sweet. Consider rotating a bronze brush, a bit oversized, with c4, just short of the rifling, every 150-200 rounds. Fast easy effective.

 

[Waltjaevel]

Those black necks can/might be caused by not removing all of the sizing lube from the cases.

As far as a carbon ring, those pics make it hard to tell exactly, but it looks like your overall chamber could use a cleaning. I, like most, tend to only see the rings form right up against the "shelf" before where the freebore and lands start.

IMO necks being too short isn't the huge deal some think it is... I've been shooting some Lapua cases that started out as 22-250Rem that I turned into 6CM cases with short necks (avg ~1.890") and after nearly 20 firings they are still barely SAAMI minimum (1.910")... and they haven't caused me any problems.

Here's a before and after of what I usually see:

View attachment 8194070View attachment 8194071

That might well be true. I use imperial sizing wax and usually just wipe it off. I guess I'll run a extra cycle in ultra sonic after resizing next time.

Have seen quite a few ruined barrels in my life and most of them because of excessive (and bad) cleaning procedures. I guess my traumas are catching up

Comparing your and my pictures it looks like there are some differences. It seems like the carbon hasn't attached so firmly yet to my bore just by the looks of the borders of the carbon areas (I hope you get the idea, explaining this in finnish would be a lot easier)

 

[Waltjaevel]

Sweet. Consider rotating a bronze brush, a bit oversized, with c4, just short of the rifling, every 150-200 rounds. Fast easy effective.

Wilco, I have a box filled with bronze brushes from way back waiting for better days

Thanks!

 

[Seymour Fish]

Wilco, I have a box filled with bronze brushes from way back waiting for better days

Thanks!

PS: I never clean brass. Wiping off the sizing lube is adequate. Keep it simple

 

[Jerry S]

Doesn’t look like a classic carbon ring. Looks more like the powder isn’t burning clean. Probably due to low pressure. I don’t think I’ve ever saw necks that dirty. I’d definitely up the charge or switch powder.

 

[Jerry S]

If you trim brass every loading there’s really no benefit to going more than .010 short of the chamber. I run mine tighter than most at .005 short of max chamber.

 

[spife7980]

Doesn’t look like a classic carbon ring. Looks more like the powder isn’t burning clean. Probably due to low pressure. I don’t think I’ve ever saw necks that dirty. I’d definitely up the charge or switch powder.

Agreed, that’s not a normal build up. Not sure it’s unbrurned but I’m curious why it’s got so damn many even little concentric rings and that it’s so dang dark. Halfway looks like someone peeled out leaving burned rubber behind lol.

Soak the hell out of it with some clr patches and see if it cleans up.

 

[CK1.0]

It's definitely a strange one... and it doesn't seem like 42gn of N555 and a 147 should be that soft of a load, Vihtavuori is listing that as max for a few different 140s... https://www.vihtavuori.com/reloading-data/rifle-reloading/?cartridge=95

 

[Waltjaevel]

I soaked it with BT C4 for 8-9 hours and tried to get it out with nylon and bronze brushes - no dice yet. Here you can see the results and I added a photo of a shot brass to show what kind of length i'm running with the case necks.

I'm using 42gn of N555, Sako LRP brass with a length of 1.910" and a CBTO of 2.264" out of a 24" Factory Tikka Tact A1 barrel. I FL size with a redding bushind die, but I don't use an expander in that die. These are all once or twice shot brass (I haven't annealed and Sako brass is harder than Lapua, might that have something to do with the excess fouling?). During load dev I went to 42,6 gn with no pressure signs - stayed in 42,0 gn because I got enough speed to get me over 1km and stabilize the bullet (2620ish fps). I also know that going over 43,5 gn with this brass and N555 goes close to compressed loads or at least forces me to use drop tubes or such.

I decided to trim to 1.910" because it was kinda in the middle of my then current brass length and I tried to get to a somewhat consistent length after trimming the longer ones and letting the shorter ones to grow a bit.

Still, I don't remember ever seeing such symmetrical carbon lines where I'm seeing them now and they go all the way down to chamber

 

[918v]

Bronze brush plus Sweets 762 solvent

 

[CK1.0]

IMO you might be dead by the time you get that out with C4/Eliminator, Sweets, Wipe-Out...

I'd recommend getting a 10" chamber rod with an oversized nylon brush on the end, putting a little abrasive (Iosso, JB, BT Chameleon, etc) on a couple/few patches, then wrap them around the nylon brush and go to town for a few...

Flush it all out really good after with 99% IPA and patches until it's literally squeaky clean.

If that doesn't work, hit it with a new tight-fitting bronze brush with penetrating oil on it and try the patches/abrasive again, that should bring it back to damn near brand new.

 

[Waltjaevel]

IMO you might be dead by the time you get that out with C4/Eliminator, Sweets, Wipe-Out...

I'd recommend getting a 10" chamber rod with an oversized nylon brush on the end, putting a little abrasive (Iosso, JB, BT Chameleon, etc) on a couple/few patches, then wrap them around the nylon brush and go to town for a few...

Flush it all out really good after with 99% IPA and patches until it's literally squeaky clean.

Agree,
I'll let it soak in C4 for the next 20 hours while I'm on a work trip but I doubt it will make a difference. I think it's only fair that while I'm working and figuring this thing out the rifle is at least trying to do its share of the job.

I have a Dewey chamber cleaning set with a good, short static rod. I think I'll order a VFG pellet adapter and scrub it with VFG bore cleaning compound (pretty same as JB, Iosso etc)

 

[Jerry S]

Bronze brush with a patch wrapped around it and a little JB paste spun with a cordless drill does wonders on carbon build up in the throat . Doesn’t hurt the chamber and only takes a couple minutes.

 

[Seymour Fish]

Bronze brush with a patch wrapped around it and a little JB paste spun with a cordless drill does wonders on carbon build up in the throat . Doesn’t hurt the chamber and only takes a couple minutes.

Winner !

 

[camocorvette]

That might well be true. I use imperial sizing wax and usually just wipe it off. I guess I'll run a extra cycle in ultra sonic after resizing next time.

Have seen quite a few ruined barrels in my life and most of them because of excessive (and bad) cleaning procedures. I guess my traumas are catching up

Comparing your and my pictures it looks like there are some differences. It seems like the carbon hasn't attached so firmly yet to my bore just by the looks of the borders of the carbon areas (I hope you get the idea, explaining this in finnish would be a lot easier)

I use imperal wax as well. Definitely sucks having to do another cleaning cycle. For me it was necessary. Wiping it off just wasn't enough.
I don't think your brass being short is the issue. Oversized brushed in the chamber and a brush for the neck are a great time saver.
I had some 223 brass that I trimmed "too" short. I set it aside for a couple years and loaded it up. Shot just fine.
If you've ever shot a bunch of 38 out a 357 mag gun you'll get what you have going on. A portion of the chamber gets caked in carbon.

 

[FredHammer]

Agree,
I'll let it soak in C4 for the next 20 hours while I'm on a work trip but I doubt it will make a difference. I think it's only fair that while I'm working and figuring this thing out the rifle is at least trying to do its share of the job.

I have a Dewey chamber cleaning set with a good, short static rod. I think I'll order a VFG pellet adapter and scrub it with VFG bore cleaning compound (pretty same as JB, Iosso etc)

Report?

 

[Waltjaevel]

Report?

Well, that was time wasted with the C4.

After next club match (this weekend) I'll take some time and paste and get this sorted out, will report back

 

[supercorndogs]

Sweet. Consider rotating a bronze brush, a bit oversized, with c4, just short of the rifling, every 150-200 rounds. Fast easy effective.

See also @Frank Green and his thread.

For the Love of God, GI Joe and John Wayne.... cleaning and abrasive cleaners

Guys..... This has been beaten to death but you have to watch how your using abrasive cleaners! Here is a 223 barrel with 800 rounds on it. Cleaned after every 75 rounds fired. I know the pitting is from a chemical reaction but I didn't get the whole story. It was cleaned approximately 10-12...

www.snipershide.com

 

[pmc847]

What if ? The carbon ring forms at the curb created by the reamer at the beginning of the bore. What if the curb is eliminated by ramping to the bore instead of the curb to the bore. normal cleaning would keeping the carbon ring at bay.

I use imperial wax too. I whip down the brass with alcohol rag.

Thoughts?

 

[spife7980]

What if ? The carbon ring forms at the curb created by the reamer at the beginning of the bore. What if the curb is eliminated by ramping to the bore instead of the curb to the bore. normal cleaning would keeping the carbon ring at bay.

I use imperial wax too. I whip down the brass with alcohol rag.

Thoughts?

How much ramping do you want?

243 is 30°

6.5 creed is 45°

If you make it too shallow of an angle it will just go on forever and youll still have the build up regardless.

 

[918v]

What if ? The carbon ring forms at the curb created by the reamer at the beginning of the bore. What if the curb is eliminated by ramping to the bore instead of the curb to the bore. normal cleaning would keeping the carbon ring at bay.

I use imperial wax too. I whip down the brass with alcohol rag.

Thoughts?

Carbon ring forms as a result of too much shooting and not enough cleaning with a bronze brush and effective solvent.

 

[pmc847]

That drawing is a great visual and good explanation. That puts that questions to bed.
thank you.

I have yet to have that problem because I do clean regularly,

cheers

 

[Waltjaevel]

Update for this,

After cleaning it with Boretech C4 and Schletek 2in1 I carefully gave it a couple of spins with J.B non-embedding bore cleaning compound just short of rifling (VFG pellets). Then gave it one pellet with Schletek 2in1 through the entire barrel. Followed by a pellet with JB cleaning compound which I passed back and forth in bore couple of times, concentrating on the 1st 3rd of the bore.

Well, everything else is almost too clean for my taste, but the rings are still there

 

[CK1.0]

Update for this,

After cleaning it with Boretech C4 and Schletek 2in1 I carefully gave it a couple of spins with J.B non-embedding bore cleaning compound just short of rifling (VFG pellets). Then gave it one pellet with Schletek 2in1 through the entire barrel. Followed by a pellet with JB cleaning compound which I passed back and forth in bore couple of times, concentrating on the 1st 3rd of the bore.

Well, everything else is almost too clean for my taste, but the rings are still there

View attachment 8218670

Weird, I'm no expert, but it almost looks like poor machining or something... maybe the chamber was cut with a worn-out toolhead and now carbon is stuck in those minuscule carved-in rings..?

Try some penetrating oil, get that area wetted down, and let it soak in for a while... there's something magical about the penetrating oil where it is able to work its way under baked-on carbon and lift it so the other cleaning shit can pull it out.

That said, "a couple spins" isn't going to do it... I'd put some JB on a large cotton patch and use some type of oversized chamber brush to spin it around until it's done what needs to be done, the abrasives are not as dangerous as some would have you believe, they're just another tool, don't overdo it and it'll be fine. Flush it all out after with IPA.

 

[Lawnboi]

Your neck is likely around .300 in diameter. If you’re not sticking a 7mm brush with a patch you’re probably not even touching it and only in the bore.

Part of my cleaning regimen is putting an oversized brush with a big patch of c4 into the neck and letting it soak overnight. (Stuck over the tip like the brush we’re a jag) Usually what results is a clean neck and it also seems to catch the lip where a ring can form.

The above technique actually chipped chunks out on barrels with a lot of carbon in them.

That said, I’m a nobody, and have no idea if what I’m doing is right.

 

[918v]

Spin a bronze brush of the correct size for the diameter you’re cleaning soaked with Sweets 7.62 solvent in a power drill.

What you did does not exert enough pressure in the carbon fouling to mechanically remove it.

 

[spife7980]

Update for this,

After cleaning it with Boretech C4 and Schletek 2in1 I carefully gave it a couple of spins with J.B non-embedding bore cleaning compound just short of rifling (VFG pellets). Then gave it one pellet with Schletek 2in1 through the entire barrel. Followed by a pellet with JB cleaning compound which I passed back and forth in bore couple of times, concentrating on the 1st 3rd of the bore.

Well, everything else is almost too clean for my taste, but the rings are still there

View attachment 8218670

Soak a patch in clr, let it sit in that spot for 5 minutes, spin it around to try and wipe it clean and then patch it dry. Bore scope again: did it take some of that black away? If it’s carbon it should have made a noticeable difference. If it doesn’t it might not be carbon. But boretech c4 sucks compared to clr.

 

[Baron23]

Update for this,

After cleaning it with Boretech C4 and Schletek 2in1 I carefully gave it a couple of spins with J.B non-embedding bore cleaning compound just short of rifling (VFG pellets). Then gave it one pellet with Schletek 2in1 through the entire barrel. Followed by a pellet with JB cleaning compound which I passed back and forth in bore couple of times, concentrating on the 1st 3rd of the bore.

Well, everything else is almost too clean for my taste, but the rings are still there

View attachment 8218670

Ah, I can't tell from your picture if you have an actual raised ring....sort of looks like flat carbon stain and not a raised ring. At the top left of the pic, that's the step up to the throat and that does look 3D and sort of clean.

As for a bronze brush in a drill or use of CLR, the guys recommending this are very experienced and ones I respect here. But I still won't do such a thing as I'm the only one paying for my barrels! haha

I do soak a bore mop in C4 and let it sit in there. As for JB paste, I follow what Frank Green recommends and wrap an oversized patch around a Parker Hale style jag (made by Dewey these days) and work that back and forth.