distance to the lands ?

[Longtrain]

Good advice

When I hear or read "carbon ring" I think of the carbon that forms just in front of the mouth of the case.
So I am not really sure if the discussion is about a carbon ring or carbon buildup in the throat area, either way the above advice is solid.

CW

For the ring and throat carbon they’re removed in the same process. Kinda like, “As long as I’m here might as well take care of both.” There are some solvents that “help” in the removal of carbon, but, an abrasive is necessary. The longer the carbon, ring or throat, stays and is continually fired upon the harder it becomes and the harder it is to remove.
Set a certain amount of rounds before you do a deep cleaning, it’s easier to manage it before it turns into diamonds.

 

[D Coots]

Short range here....I go after it every time I clean....No abrasives needed. Different disciplines, different methods.

 

[Mulligan]

Short range here....I go after it every time I clean....No abrasives needed. Different disciplines, different methods.

How do you address the carbon issue?
CW

 

[D Coots]

Short range, clean often. Use wipe out products...2 wet patch and then 7mm nylon brush in my 6PPC..after brushing with w/o patch out and accelerator I wipe the rod dry and push up against the throat and spin 25 or so strokes. Carbon ring is still present, but a dark color, not a buildup.

 

[Kracken McGraw]

You need to use the same physical bullets to make a comparison, especially when using Sierras. The LTO on Sierras can vary significantly bullet to bullet. This will skew your results.

My Nosler Custom Competition bullets are worse.

 

[rebs]

As in my original post my lands have moved .030 what would you guys do as far as reloading and seating depth. Erik Cortina says not to chase the lands. So do you guys think you would move the bullet out farther or load the same depth that I was ?

 

[SKWERLZ]

As in my original post my lands have moved .030 what would you guys do as far as reloading and seating depth. Erik Cortina says not to chase the lands. So do you guys think you would move the bullet out farther or load the same depth that I was ?

If it’s still shooting good leave it.
I’ve had two 7mm barrels that had the same OAL for the entire life of barrel and shoot fantastic the whole time.
If it got out of tune a bit go in whatever direction you want( in if magazine limits oal or out if no restrictions on oal) in small increments, 2-3 thousandths, probably in 1-3 steps of that you’ll be back in business.

 

[rebs]

If it’s still shooting good leave it.
I’ve had two 7mm barrels that had the same OAL for the entire life of barrel and shoot fantastic the whole time.
If it got out of tune a bit go in whatever direction you want( in if magazine limits oal or out if no restrictions on oal) in small increments, 2-3 thousandths, probably in 1-3 steps of that you’ll be back in business.

Thank you

 

[marine52]

You need to use the same physical bullets to make a comparison, especially when using Sierras. The LTO on Sierras can vary significantly bullet to bullet. This will skew your results.

This is absolutely correct. When you are measuring changes in distance to lands over time, make sure you use the same bullet or at least a bullet from the same lot. Bullet base-to-ogive can differ significantly between lots. Ned Ludd Pointed this out to me a few years ago when I had a similar question. See thread below

308 throat erosion

For you F-TR guys: I have a 308 Bartlein barrel with 788 rounds down the tube. Reamer used had .202 freebore. 600 of the 788 rounds were 200.20x Bergers with .010 jump and 44.2 grains of Varget. The other 188 were experiments with Warner Flatline 180s with 43.2 grains of H4895. I just check...

forum.accurateshooter.com

 

[rebs]

If it’s still shooting good leave it.
I’ve had two 7mm barrels that had the same OAL for the entire life of barrel and shoot fantastic the whole time.
If it got out of tune a bit go in whatever direction you want( in if magazine limits oal or out if no restrictions on oal) in small increments, 2-3 thousandths, probably in 1-3 steps of that you’ll be back in business.

I loaded my original load at the same seating depth and it shot great. No need to chase the lands in my barrel.