Carbon ring on belted mag

[LVJ76]

Yes I know, tons of carbon ring threads
already, but this one is mine Lol.

So in the 35+ years of shooting centerfire rifles I've never ever had one before and I dont have a bore scope, at least not yet, so here is the issue.

I started getting a sticky bolt on my 7mm Rem Mag on loads that have not give me pressure issues, and I started seeing scratches right above the belt.

Then I loaded a reloaded round without firing it, and also got a sticky bolt on extraction of the live round, tried a factory round also without firing it and same issue, sticky bolt and both showed scratches above the belt.

I scrubbed it a bit the other day and still sticky bolt with live rounds.

So tonight I'm leaving it overnight soaking with a patch with solvent and I'll give it another good scrub in the morning hoping that'll fix it.

I clean my rifles thoroughly every 100 to 120 rounds and never had this issue before so the question is, is this a Belted Magnum issue?

Note, the belt has never been an issue for me so please save me the lecture on how belted magnums are bad cause I love mine and dont plan on getting rid of it anytime soon.

Attached are images of a fired brass and second a loaded round, kind of hard to capture the scratches with the phone camera but are easily seen with the naked eye especially againt the light.

Thanks in advance and stay safe

 

[Deputy819]

How many firings on that brass and what die(s) do you use for sizing?

Get one of these...

https://www.amazon.com/Teslong-Borescope-Side-View-Semi-Rigid-Smartphone/dp/B07TTQF24F

 

[LVJ76]

How many firings on that brass and what die(s) do you use for sizing?

Get one of these...

https://www.amazon.com/Teslong-Borescope-Side-View-Semi-Rigid-Smartphone/dp/B07TTQF24F

Thanks Deputy. That's the plan, I saw it on amazon the other day.

I've always neck sized only and always used RCBS dies. I do full size after 4 or 5 firings and then back to neck sizing. This brass has 3 firings and when I load the round it goes im very smooth.

Now I know it's not a brass sizing issue because it happens with factory rounds as well.

I removed the wet patches this morning and scrubbed a little more. Then I tried both reloads and factory and both extracted with no issues so that is a good sign. Now off to the range to verify some loads and sight in for next weeks javelina hunt. We'll see what happens.

Thanks again and stay safe out there

 

[cape cove]

I don't believe your problem is a carbon ring. What is happening is your case is enlarging just in front of the belt . This happens from time to time in belted mags when you have a die that does not match up good with your chamber. If you would happen to have a 300 Win /300 Weatherby/ STW sizing die on hand you could try screwing it down tight against your shell holder and running your 7mm Rem case all the way up in the die. This may get that area sized if not then you may require a Larry Willis die. JMO

Innovative Technologies - Reloading Equipment

Our patented resizing die can reload Winchester, Remington and Weatherby belted magnums up to 20 times, instead of just 2 or 3 times and the top of the die is a chamber width gauge.

www.larrywillis.com

 

[Deleted member 103481]

I don't believe your problem is a carbon ring. What is happening is your case is enlarging just in front of the belt . This happens from time to time in belted mags when you have a die that does not match up good with your chamber. If you would happen to have a 300 Win /300 Weatherby/ STW sizing die on hand you could try screwing it down tight against your shell holder and running your 7mm Rem case all the way up in the die. This may get that area sized if not then you may require a Larry Willis die. JMO

Innovative Technologies - Reloading Equipment

Our patented resizing die can reload Winchester, Remington and Weatherby belted magnums up to 20 times, instead of just 2 or 3 times and the top of the die is a chamber width gauge.

www.larrywillis.com

OP is saying same issue with new Unfired cases.

OP maybe I missed it, do you clean with bronze brushes? Interested in the outcome on this one. Wish you had a scope

 

[cape cove]

I can't see how a carbon ring is going to mark a case just in front of the belt. The ring is at the other end of the chamber.

 

[Deleted member 103481]

I can't see how a carbon ring is going to mark a case just in front of the belt. The ring is at the other end of the chamber.

My rambling thoughts, so worth very little if even your time.

perhaps we are assuming too quickly that the marks above the belt are the (only) cause of the sticky bolt. Perhaps they are not the cause, but just a symptom of the main problem, the carbon buildup.

unfired case has issues with sticking from carbon buildup

Fired case has issues with sticking from carbon buildup

Carbon buildup also causes increased pressure/expansion above web in fired cases

how else does this problem get solved in both fired and unfired cases purely by OP soaking/cleaning the rifle overnight?

 

[Deputy819]

Thanks Deputy. That's the plan, I saw it on amazon the other day.

I've always neck sized only and always used RCBS dies. I do full size after 4 or 5 firings and then back to neck sizing. This brass has 3 firings and when I load the round it goes im very smooth.

You betcha! I do the same thing (with Redding dies) and I also have one of those neat little Larry Willis toys linked by 'Cape Cove' in #4 and was gonna suggest it, but if your reloads (and factory stuff) chamber just fine then maybe the web 'growing' isn't your issue......yet. Have fun at the range.......we're prepping for an ice storm here.

 

[cape cove]

@Igottasnakeinmyboot You make a good point. I guess we will have to wait and see how the OP makes out. I had this problem with my 270 Weatherby. Brass markings in the very same place . Turned out to be what I posted earlier. If it was a bad carbon ring then you would think it would mark the bullet also by pinching it thus causing higher pressure. The only carbon rings I have had in the past (in my 6mm BR) formed at the mouth of the case, marking the bullet and raising pressure by pinching the projectile and hurting accuracy. JME

 

[Deputy819]

What you said in #4 was the first thing that came to my mind as well.

 

[LVJ76]

Alright, so live rounds now feed and extract with no issues.

Fired rounds both factory and reloads get sticky, not as bad as before but still though no scratch marks now.

So I'll do another two wet patch soakings and see what happens. I clean this rifle just like my other 3 7mm-08's but the others don't have a belt, so maybe that is the issue causing what I believe is a carbon ring.

Note: the wet patches were very very dirty when I pulled them out this morning.

I believe the carbon gets stuck at the belt and that's whats causing it, what do you all think?

Thanks everyone for your input and stay safe

 

[Deleted member 103481]

Alright, so live rounds now feed and extract with no issues.

Fired rounds both factory and reloads get sticky, not as bad as before but still though no scratch marks now.

So I'll do another two wet patch soakings and see what happens. I clean this rifle just like my other 3 7mm-08's but the others don't have a belt, so maybe that is the issue causing what I believe is a carbon ring.

Note: the wet patches were very very dirty when I pulled them out this morning.

I believe the carbon gets stuck at the belt and that's whats causing it, what do you all think?

Thanks everyone for your input and stay safe

Not using those nylon brushes made for brass necks are you?

 

[LVJ76]

You betcha! I do the same thing (with Redding dies) and I also have one of those neat little Larry Willis toys linked by 'Cape Cove' in #4 and was gonna suggest it, but if your reloads (and factory stuff) chamber just fine then maybe the web 'growing' isn't your issue......yet. Have fun at the range.......we're prepping for an ice storm here.

I'll take any storm right now, well except a dust one, we already get those often. We got some rain and snow a couple weeks ago but nowhere near enought what we need. Very dry still.

Thanks again and stay safe

Not using those nylon brushes made for brass necks are you?

no I am not Lol. Thanks for the input, appreciate it.

 

[AZShooter]

.Best of luck with your chambering issue. And stay out of my javelina area next week! <grin>