Strange Case Markings?

[JTinTexas]

I have been a member of this forum for a long time (JackT) and have found it to be very helpful and at times entertaining. I reload multiple calibers and after shooting my 6x47 Lapua, I noticed these strange markings on several cases after I got home. It appears to be carbon and I can rub it off with some effort. Any thoughts on what causes this and should I be concerned?

Thanks in advance for the help!

 

[P1ZombieKiller]

Looks like Sharpie pen marks to me (file this under the "and at times entertaining" part since I doubt it is very helpful).

 

[KMart]

I agree with P1Z and must say that I have never seen defined marks like that created by firing the round.

 

[Walt Krafft]

Low pressure loading?

 

[JFrank]

Low pressure loading?

Looks that way to me also

 

[6.5 forever]

Wow. Maybe a very dirty chamber. Humidity and wild temperature swings here in the west have been affecting my chambers more than barrels.
Ammo sits out freezing, warms up in the chamber and sheds moisture when fired???

 

[JFrank]

I get similar carbon build up when fire forming with modest charges.

Low pressure loading?

 

[6.5 forever]

Also what are those grooves in your case neck?

 

[P1ZombieKiller]

@JTinTexas are you talking about the markings on your necks? or the line markings on the case bodies?

 

[JTinTexas]

I am talking about the line markings on the case body. They are not from a sharpie and based on Quickload the pressure was in the range of 55,300 psi. .

 

[rwj]

I am talking about the line markings on the case body. They are not from a sharpie and based on Quickload the pressure was in the range of 55,300 psi. .

Are there corresponding marks on the chamber wall?

 

[ScottVA]

With all due respect, I'd be more concerned about the case necks. Look closely @SPJ case neck with similar carbon footprint...minus the grooves the cutter left in the neck.

 

[Highpower-FClass]

I have been a member of this forum for a long time (JackT) and have found it to be very helpful and at times entertaining. I reload multiple calibers and after shooting my 6x47 Lapua, I noticed these strange markings on several cases after I got home. It appears to be carbon and I can rub it off with some effort. Any thoughts on what causes this and should I be concerned?

Thanks in advance for the help!

View attachment 1399361

Any chance you stored the spent cases in a ammo box which has some sort of dirt / oil where the cases rub against the ammo box walls? I had that happen with 223 cases stored in a Lapua ammo box. My imprints were much more symmetric and not quite as pronounced but nevertheless.

 

[Ggmac]

what kind of case carrier do you use

 

[6MMsteve]

yes the case nks look hogged and not a finish cut, pretty rough, I hate turning nks, but I always made them look good with a light finish cut or steel wooly..I don't turn anymore and I'm very happy that rabbit hole is plugged

 

[LCazador]

I have been a member of this forum for a long time (JackT) and have found it to be very helpful and at times entertaining. I reload multiple calibers and after shooting my 6x47 Lapua, I noticed these strange markings on several cases after I got home. It appears to be carbon and I can rub it off with some effort. Any thoughts on what causes this and should I be concerned?

Thanks in advance for the help!

View attachment 1399361

Is this the first firing on these cases? Good pressure for fireform. Necks look they have neck turned and the cutter didn't make a smooth cut. If this is first firing I wouldn't worry much, if it's your load that you intend to use, than I'd be looking into another load.

 

[M-61]

I thought at first you were asking about the necks. Carbon on the neck is not a shocker when I look at the roughness of them.
In fact I see you are referring to what appears as sharpie marks.
Never saw that before. Sorry.

 

[esromvre1]

Let's see a before and after viewing

 

[JTinTexas]

This is the fourth firing on the cases and they are stored in clean condition. I will clean off the carbon marks (not a sharpie) steel wool the necks smooth and then see if it happens again; and if so, present a before and after shot.

I typically shoot fairly light loads, no reason to burn out the barrel any sooner than I need to and hard not to be pleased with the load.... (see pic).

Thanks for the help guys.

 

[ebb]

Are the marks on all the brass or just the 3 ?