Time for a New Barrel? -- Borescope Video

[Chaotik]

This is a Teslong borescope video of my barrel. I would like opinions from the experts.... the barrel has just been cleaned with Free All, BBS with a bronze brush, overnight soaked and brushed with wipe out and another overnight soak with C4. It has also been aggressively scrubbed with JB borepaste.
It's a 6mm dasher Krieger barrel on a Borden action with just over 1000 rounds on it, and we (the rifle and I) did not perform well in the last couple of LRBR matches.

 

[C.E.Smith043]

How did it perform around the 200 -600 round mark?

 

[Chaotik]

How did it perform around the 200 -600 round mark?

It was great up until about 850 rounds, and ended up winning an overall 2 gun in a very competitive LRBR field.

 

[JMayo]

The chamber mouth shows allot of hot use but the real measure is about 2-4 inches down the barrel from there. IMO

My 6bra gets that way toward it's end of competition life but it still has allot of 10 ring life left. I've shot 2" @ 600yds úp around 2k rounds.

 

[urbanrifleman]

Shoot 5 Tubb TMS bullets at 2000 fps and try it again.

 

[ShtrRdy]

Have you tried working up a new load?

 

[Chaotik]

Have you tried working up a new load?

No, as I really don't want to waste components or my time if this barrel is done, as I have other rifles and other barrels.

 

[jelenko]

That looks like just the freebore area [yes?] with a fair amount of hard carbon. The carbon can be removed with JB or Iosso or Flitz bore cleaner. I have found JB takes a lot more cycles than either Iosso or Flitz. From my experience, the amount of hard carbon in the pic would take ~ 10 'sessions' of Iosso on a tight fitting patch wrapped around a Parker Hale jag - with each 'session' being 10 full cycles.
FYI. Someone pointed out that carbon settles in the bottom half of the bore => so the bottom half will show hard carbon after the top half is clean.

In the area shown, the issue would be a carbon ring affecting pressure and accuracy. From the pic, it doesn't look as solid as some I've seen, but could be contributing to loss of accuracy.

As mentioned, what would be more interesting is what the bore looks like 2-4 inches in. In that area, we're looking for fire cracking. The heavier the fire cracking, the more likely accuracy is being impacted.
Again, just from the pic, the freebore area doesn't appear to have fire cracking in it which would indicate there would be little if any firecracking further into the bore.

 

[powderbrake]

Not aggressive enough. Very dirty neck and bore. Try the JB with a bronze brush, keep scrubbing until all the black is gone in the barrel.
An oversize bronze brush and JB in a drill will wipe that carbon out of the neck.
Follow up with a light oil like Kroil.

When the entire chamber. neck, freebore and lands/grooves show no black, the barrel is clean, so try your regular loads again.

 

[Walt Krafft]

If you are doubting it, get a new one coming.

 

[Dusty Stevens]

Its always time for a new barrel. They are components

 

[Chaotik]

If you are doubting it, get a new one coming.

I was planning on shooting this gun in a few more matches in the next couple of months before getting it rebarreled.... but that plan may have to change.

 

[Acyr]

Doesn't look terrible. Scrub it some more, recheck distance to lands and shoot it.
Get a new one on the way. They don't last forever lol.

 

[jelenko]

Doesn't look terrible. Scrub it some more, recheck distance to lands and shoot it.
Get a new one on the way. They don't last forever lol.

+ a couple.

 

[DaveTooley]

No, as I really don't want to waste components or my time if this barrel is done, as I have other rifles and other barrels.

It could be as simple as a seating depth change. Probably wouldn't take 15 shoots.
Get some good conditions and shoot 200 yds. Compare before and after at the same range session.

 

[Clancy]

I’ve seen worse shoot really well. 2 things I do after a super aggressive cleaning, which I don’t think you quite got to, are adjust my seating depth AGAIN and definitely run lock ease after cleaning. I think that really helps with the fouling.

Do order another one pronto though, she’s on her way out.

 

[Clancy]

It could be as simple as a seating depth change. Probably wouldn't take 15 shoots.
Get some good conditions and shoot 200 yds. Compare before and after at the same range session.

You spoke it as I was typing, thank you sir.

 

[gunsandgunsmithing]

It doesn't look too bad to me. I'd buy it if you want to sell it reasonably. May be a good candidate for a setback.

 

[gme]

looks like a fairly typical middle aged barrel to me, there's still some carbon present, I'd re check the distance to the lands and adjust it, also try adjusting the load and try again, did you inspect the muzzle? Lots of times the trouble is at the other end.

 

[jelenko]

looks like a fairly typical middle aged barrel to me, there's still some carbon present, I'd re check the distance to the lands and adjust it, also try adjusting the load and try again, did you inspect the muzzle? Lots of times the trouble is at the other end.

Gary - How well would one of those brass 'buttons' from Brownells with lapping compound work to restore a muzzle? Assuming you're looking for 1/2 - 3/4 MOA groups? I.e., not for benchrest accuracy?