Eroded throat?

[Addicting]

I’ve been trying new bullets in my rifle and am having troubles.

I started with Etips and couldn’t get them to group to save my life. I went back to a known accubond load and it still groups sub MOA. Now I picked up some Barnes 127g LRX and am trying to find the lands with my Hornady OAL gauge.

Same issue as the Etips. When I inserted the OAL gauge and slid the bullet forward you can feel 3 very distinct hits and slight resistance against the bullet. Depths range from 2.207 to 2.274.

I checked my wife’s rifle chamber and it is constantly 2.254.

Cleaned the hell out of it to ensure there wasn’t any carbon or copper in the throat. Still did it, I remember it doing with the Etips too, but it only had 2 points of resistance.

The rifle round count is 700 or so. I’ve only had it 3 years am the only owner. Thinking it’s time to get it bore scoped as I can’t see anything obvious with my eyes.

I’ve never shot out a barrel before so this is new territory for me. What say you more experienced guys?

Thanks Tony

 

[Bigjay73]

I know you said you cleaned it, but sounds like a carbon ring buildup. That stuff can be hell to remove. Have it scoped, may have a bunch of copper in the rifling as well

 

[rtraverdavis]

What cartridge?

 

[noharleyyet]

...guessing a .264 or .277 cal?

...tryin to slip a manbun by us?

 

[rtraverdavis]

700 rounds would be awfully fast to erode a manbun throat...

Lots of dirty euphemisms to go with that statement. I’ll let you guys have at it.

 

[Addicting]

Yep, it’s a man bun eating Creedmoor. I was trying not to use that “swear” in front of so many 7mmHT guys.

 

[Addicting]

I know you said you cleaned it, but sounds like a carbon ring buildup. That stuff can be hell to remove. Have it scoped, may have a bunch of copper in the rifling as well

You were spot on. There was a large carbon ring in it. Cleaned it out and found some chatter marks underneath it. You can see where the case stops. From there past the chatter marks was all carbon. Gunsmith said it will just keep doing it. He wanted the other smith to look at it. He was not sure how involved it would be to try and fix it verses just managing it ever couple hundred rounds.

 

[std7mag]

Can't really tell what i'm seeing.. Lol
You could always try to run a Manbun finish reamer in it to see if it will clean up any.
Try not to go deeper though.

Other than that, maybe a swab with some 600 grit grinding compound.

Just throwing things out there.

 

[Addicting]

Yeah, I definitely don’t want to go deeper. I have 200 rounds here set to that chamber spec.

Those chatter marks are at the beginning of the rifling. I hope they can take it out or at least smooth them with some 600 grit or polishing.

 

[Bigjay73]

Damn, that's unfortunate. Wonder if an abrasive compound would remove any of that. Hopefully you haven't lost any permanent accuracy, and cleaning it often will keep it going for a while.

 

[Addicting]

Damn, that's unfortunate. Wonder if an abrasive compound would remove any of that. Hopefully you haven't lost any permanent accuracy, and cleaning it often will keep it going for a while.

We had to use abrasive compound on a oversized brass brush to get the carbon out. Which may be what I have to do from now on out.

Last time I shot it, it would still cloverleaf at 100 with accubonds.

 

[cahunter805]

I’d just keep cleaning the carbon ring out every few hundred rounds. Use JB bore paste or the oversized bronze brush with boretech carbon cleaner.
If you keep an eye on it it’s not to much trouble!

 

[Deleted member 20812]

I’d just keep cleaning the carbon ring out every few hundred rounds. Use JB bore paste or the oversized bronze brush with boretech carbon cleaner.
If you keep an eye on it it’s not to much trouble!

Another vote for JBs. Great stuff

 

[Bigjay73]

Issoso is another option if you can't find JBs

 

[Bigjay73]

You guys dont think using a rubbing compound every couple hundred rounds would remove enough material in the chamber to cause an issue? I agree that that is what he should do, just wondering if it could cause other problems down the road.

 

[Deleted member 20812]

You guys dont think using a rubbing compound every couple hundred rounds would remove enough material in the chamber to cause an issue? I agree that that is what he should do, just wondering if it could cause other problems down the road.

I doubt I’m going to spend enough time with it to remove steel.

 

[Bigjay73]

Probably not. I'm good at overthinking things