What the heck is this?

[Creedmoor shooter]

New one for me. Decided to try to and find where my lands are at now. Well I couldnt. I started at 3.310(with comparator attached) and went all the way down to 3.250. These strange marks appear on every piece of brass. I do not see any of the 6 grooves on the barrel so I'm not sure where my lands are now. The rounds go in alittle mean and come out mean and this is what the bullet looks like. Its badly scratched all the way around. I can feel the scratches with my finger nail. Anyone have any ideas? 6.5 creed 1500-1700 hot rounds down the pipe. Smith thinks possibly the barrel is going bye bye. I was wondering if a carbon ring would cause this. What do you guys think?

 

[birdiemc]

I'm confused, if you're trying to find the lands why did you continue to push the bullet farther into the case? If it didnt reach at 3.310 it's not going to reach at a shorter measurement.
The carbon ring would be the thing I would suspect for the scratching on the bullet if it's all the way around. How well do you clean? One of those $50 borescopes from amazon would probably save you a lot of head scratching.

 

[cape cove]

If you done this before with this rifle and no marks and they are there now then I don't know what it could be other than a carbon ring.

 

[Creedmoor shooter]

I'm confused, if you're trying to find the lands why did you continue to push the bullet farther into the case? If it didnt reach at 3.310 it's not going to reach at a shorter measurement.
The carbon ring would be the thing I would suspect for the scratching on the bullet if it's all the way around. How well do you clean? One of those $50 borescopes from amazon would probably save you a lot of head scratching.

I went deeper because of the scratches. I wanted to see if they went away. I went back to 3.250 and the scratches are still there. Not as bad but still there. They are all the way around the bullet

 

[Creedmoor shooter]

If you done this before with this rifle and no marks and they are there now then I don't what it could be other than a carbon ring.

My thoughts exactly.

 

[LongRange338]

Take a sharpie and color your bullet then start shorter and proceed to try to find the lands. You will need to chamber/extract with a lot of care but this could help identify any marks on the bullet.

 

[codyadams]

That is odd. I have had a savage that would only scratch the bullet on one side, but that is because one of the lands was shorter than the others, on the new barrel. Good ol factory rifle stuff.

Just get a borescope, that should tell ya whats going on. Then likely, scrub out the carbon ring. My best guess anyway.

 

[Creedmoor shooter]

That is odd. I have had a savage that would only scratch the bullet on one side, but that is because one of the lands was shorter than the others, on the new barrel. Good ol factory rifle stuff.

Just get a borescope, that should tell ya whats going on. Then likely, scrub out the carbon ring. My best guess anyway.

Ya I'm going to buy a bore scope. It will let me know what kind of throat erosion I have as well. I've never had a carbon ring before. Any tips on removing one?

 

[aushunter1]

How many rounds through the rifle?
Throat errosion maybe??

 

[Savage 12BVSS]

If you are at 1500-1700 rounds down the pipe I would expect some throat erosion and carbon build up as well. Do a good cleaning especially in the chamber area and work your way out slowly to the lands, they won't touch all the way around like that, build up is scratching bullet IMHO.

 

[Creedmoor shooter]

If you are at 1500-1700 rounds down the pipe I would expect some throat erosion and carbon build up as well. Do a good cleaning especially in the chamber area and work your way out slowly to the lands, they won't touch all the way around like that, build up is scratching bullet IMHO.

That's what I was thinking. I just wanted to run it by everyone. I'll get a bore scope coming on monday and really see what happening. I dont expect this barrel to last another 500-700 rounds but one never knows. Hate to have it go on me mid match. I have another barrel already waiting I just want to get every bit of life I can out of this one

 

[Creedmoor shooter]

How many rounds through the rifle?
Throat errosion maybe??

1500-1700. Smith said possibly throat erosion but I didnt actually take the rifle to him. Rifle still shoots somewhat ok. This was a 7 shot group that measured. 661

 

[Vol1975]

1500-1700. Smith said possibly throat erosion but I didnt actually take the rifle to him. Rifle still shoots somewhat ok. This was a 7 shot group that measured. 661View attachment 168653

Clean really good but at end of the day id tell u to shoot it until it stops shooting the the way you want. With that many rounds down range I'd probably start planning looking at barrel replacements. Had a gun that had the throat and lands was wore a fair amount but would still shoot 1.5 Moa for a hunting rifle. At the end of the day gave me time to plan a replacement.

I don't shoot competition so I'm in familiar with this problem with carbon ring. Probably BC I don't shoot enough of a string and I clean regularly after hunting season. cheers.

 

[Creedmoor shooter]

Clean really good but at end of the day id tell u to shoot it until it stops shooting the the way you want. With that many rounds down range I'd probably start planning looking at barrel replacements. Had a gun that had the throat and lands was wore a fair amount but would still shoot 1.5 Moa for a hunting rifle. At the end of the day gave me time to plan a replacement.

I don't shoot competition so I'm in familiar with this problem with carbon ring. Probably BC I don't shoot enough of a string and I clean regularly after hunting season. cheers.

pretty much anything larger than .5-.6moa is no good to me. Tight now shes right on the edge of pulling for me. I realize at the end of the day this barrel is probably past its usefulness to me. I'd still like to bore scope it and see what's going on. I'm sure there is some pretty good throat erosion especially as hot as I've ran it.