300 rum throat fouling

[Lefty7mmstw]

Why are you so worried about your throat?
They erode, no matter how often you scrape it, polish it or any other thing you do to it, it WILL get larger and longer. How it looks has NO impact on accuracy, if it's dull that's because it has eroded and has haze cracking, normal wear, nothing more. What kills accuracy is how FAR it has eroded DOWN the barrel, increasing the LENGTH to the origin of the rifling.
How much has your velocity dropped with the SAME load over the last 8 years?
If it is substantial, say 150-200fps, then yes, your throat is eroded and accuracy will gradually lessen off, how much you ask, no body knows, but barrels just don't go 'bad' overnight.
BTW, the carbon ring is a good thing, it keeps your bullets straight!
I shoot comp in 200 round strings, never do I clean after a 60+ round match, never!!
I've seen more barrels ruined by excessive cleaning than I have from excessive shooting!!

Cheers.
lightbulb

I am worried about the throat mainly because of the rate of fouling. Only a few shots baked it in enough that it was hell to get it out. The barrel is shooting pretty much how it always has accuracy and speed wise.

 

[shortgrass]

It's problems like this that make a bore scope "worth its weight". Is it carbon build up or is it fire cracking (or both)? A close up look would answer that question. Just as an added thought, most barrels I see that the owner wants "set-back & re-chambered/head spaced" are way past that. They wait too long. I had a Hart MTU contour bbl. chambered in 6.5mm x .300RUM come to me with a full length bbl. shank that had some serious throat erosion/fire cracking. I cut 3 3/16" off of it, threaded it, and chambered it in .264 Win. Mag. The cracking was still visible ahead of the chamber, but the 'cracks' hadn't started to 'curl' into the bore, yet. I can't help but wonder how many more rds. the guy got out of it and what kind of accuracy he was getting. If it'd have been mine, with the amount of cracking in it, I doubt I'd have re-chambered it for the cost. The point, if setting back is 'in the cards',,,,, don't wait too long. Especially if it's a high intensity rd.

 

[Lefty7mmstw]

It's problems like this that make a bore scope "worth its weight". Is it carbon build up or is it fire cracking (or both)? A close up look would answer that question. Just as an added thought, most barrels I see that the owner wants "set-back & re-chambered/head spaced" are way past that. They wait too long. I had a Hart MTU contour bbl. chambered in 6.5mm x .300RUM come to me with a full length bbl. shank that had some serious throat erosion/fire cracking. I cut 3 3/16" off of it, threaded it, and chambered it in .264 Win. Mag. The cracking was still visible ahead of the chamber, but the 'cracks' hadn't started to 'curl' into the bore, yet. I can't help but wonder how many more rds. the guy got out of it and what kind of accuracy he was getting. If it'd have been mine, with the amount of cracking in it, I doubt I'd have re-chambered it for the cost. The point, if setting back is 'in the cards',,,,, don't wait too long. Especially if it's a high intensity rd.

she's shooting again, with little visible darkening in the throat area.

I fired a few groups today with it, and after the first group, which I didn't even try to hold well on (it has always wanted a couple of shots to foul), the next three groups were sub moa. The 225 hdy with rl33 held .7moa and the 180 interlock with rl25 held .6 moa. This was @ the local 200 (actually 201) yard range with a flaky wind @ about 8 o'clock.

The interesting thing was the cleaning.... She cleaned up with little effort as is usual with the rifle. There were no abnormal fouling deposits left in the throat. This will be something to watch with the rifle from now on I guess.

Thank you on the now rather than later comment on the set back... I'm rather inclined to "let her buck" and put a stainless barrel on it when the barrel fully goes south. The action needs trueing anyway... Good excuse to kill two birds with a big fat wallet...