Experts please advise: inexplicable barrel fouling - affecting accuracy - "lumps" in lands

[Utectok]

All my full bore centerfires throw Barnes tsx or ttsx. None of the others have any throat cracking.

Indeed, I have never heard of throat-cracking being attributed to projectile hardness. Throat land thinning - yes, cracking - no. Do you have a link to data that links cracking to projectile hardness?

My 6.5x55mm has not experienced any of the common reasons given for throat-cracking:

• over-pressure, over-temperature or combination thereof [unlikely given almost exclusive diet of Sako factory ammunition]
• rapid-fire usage [I am a deerstalker: Range time reflects cold bore conditions per field use]
• very high round count [ 600 rounds is not generally considered a high count]

It really is a wierd one in be pretty miffed if my barrel looked like that after 600 rounds! I know mine has a few divots like yours but not that level of fire cracking, plus I hardly ever clean it and it shots 2” groups at 350m if I do my part

 

[User00026]

What make of rifle/barrel is this?

 

[Sharpie]

Who needs a borescope if you have one of these ?

WWI Pattern Armourers Bore Viewer Tool for Enfields

WWI Pattern Armourers Bore Viewer Tool for Enfields. Simply hold in breech of rifle, view from muzzle, mirror reflects light for barrel inspection.

www.henrykrank.com

PS: have you considered trying electrolysis ? Will certainly get iron oxides out, and also copper. Never tried it, but the science is sound.

I agree that that that firecracking looks horrendous ( not that I know much about this) and possibly bits of it may have broken off, got into the grooves, then created the pits once forced into them.

Why are there no pits seen in the lands ? If they were due to inclusions in the steel during manufacture I would expect them to be evenly distributed between lands and grooves. Therefore I suspect that they have been induced by the above process.

I am also puzzled by the longitudinal striations in the grooves, and also lands, seen all the way down the barrel and even at the muzzle. Suggesting to me that they have been there since new. And may have formed a "starter" for the fire cracking to develop.

What do your other good barrels look like ? Similar or different ?

What powder are you using ?

TBH, if it looks this bad after only 600 rounds, it is not going to improve with further shooting, I think your "cheesegrater" view of the effects on copper (or gilding metal jacketed lead) is apt. You seem to have got the rest of the barrel pretty clean now, so if it still won't shoot, probably time for a new barrel. And of course, borescope it first before accepting it, in case you can see anything untoward, or different, from your good ones.

There is of course the "firelapping" concept, that allegedly might smooth out some parts such as the throat, but I'd have to be absolutely desperate to consider putting abrasive coated bullets down a barrel.

 

[zambezi]

What make of rifle/barrel is this?

Experts please advise: inexplicable barrel fouling - affecting accuracy - "lumps" in lands

I'm no expert, but "heat" relating to a barrel, is usually caused by "Rapid fire". This can produce fire cracking in surprisingly few rounds.

www.thestalkingdirectory.co.uk

 

[sharkbait]

I thought I'd cleaned mine too before I bought a bore scope! Jeeez what an eye opener my barrels felt silky smooth when i took a look copper fouling still there, i soaked the barrels overnight cleaned re cleaned more soaking and kept at it after a while the copper fouling went to my relief!

 

[User00026]

Have you slugged it and measured it it’s an oversize bore? If not, could also just be a bad batch of steel or a cock up in production hardening/stabilisation

I’d be asking Blaser to explain and compensate no matter what time has passed

 

[zambezi]

I have tried all cleaning products suggested to me in this thread, and elsewhere, and it is now clear that this barrel has throat damage which cleaning cannot remediate.

So I have contacted Blaser Group UK, and they have agreed to review the barrel. It is with the RFD for shipment as we speak.

What I made utterly clear to the Blaser UK chap is that the barrel has been very accurate and has given very good service. Albeit for an unseasonably short life. So I do not expect gratis replacement.

In my mind's eye, a modern barrel fed moderate factory fodder should make 2500-3500 rounds before showing significant wear. Sound about right? [obviously, not a hard-n-fast rule, but correct for this type of use: cold-bore factory loads, regular maintenance...?]

Since mine has given up the will at circa 600 rounds fired, I estimate it to have served 20-25% of an expected barrel life under the conditions in which I used it. Hopefully Blaser feel likewise.

 

[Utectok]

I have tried all cleaning products suggested to me in this thread, and elsewhere, and it is now clear that this barrel has throat damage which cleaning cannot remediate.

So I have contacted Blaser Group UK, and they have agreed to review the barrel. It is with the RFD for shipment as we speak.

What I made utterly clear to the Blaser UK chap is that the barrel has been very accurate and has given very good service. Albeit for an unseasonably short life. So I do not expect gratis replacement.

In my mind's eye, a modern barrel fed moderate factory fodder should make 2500-3500 rounds before showing significant wear. Sound about right? [obviously, not a hard-n-fast rule, but correct for this type of use: cold-bore factory loads, regular maintenance...?]

Since mine has given up the will at circa 600 rounds fired, I estimate it to have served 20-25% of an expected barrel life under the conditions in which I used it. Hopefully Blaser feel likewise.

Right choice buddy good luck

 

[zambezi]

Blaser Group have been excellent: They requested I send barrel for inspection. Inside of a week they adjudicated that this was a warranty replacement situation and my RFD is now in possession of the replacement barrel.

I had hoped Devon and Cornwall Firearms could accommodate the barrel serial number change without formal variation paperwork, but it seems not...

So variation has been submitted. I do hope the paperwork can be turned around fairly quickly. My next stalk is probably best served with this new barrel.

 

[Utectok]

Blaser Group have been excellent: They requested I send barrel for inspection. Inside of a week they adjudicated that this was a warranty replacement situation and my RFD is now in possession of the replacement barrel.

I had hoped Devon and Cornwall Firearms could accommodate the barrel serial number change without formal variation paperwork, but it seems not...

So variation has been submitted. I do hope the paperwork can be turned around fairly quickly. My next stalk is probably best served with this new barrel.

That’s great news !

 

[zambezi]

D&C have obviously been busy: paperwork to acknowledge serial number for my new barrel has taken 3 months. But I am told it should arrive this week. My very patient RFD will finally be able to get the barrel out of his armoury.

Circling back to the Gunex vs Ballistol experiment I started all those months ago, the result is definitely a win for Gunex. The Ballistol section of the test piece now shows uniform surface rust and the Ballistol marker pen label is gone. The Gunex side remains intact :

 

[Steff]

D&C have obviously been busy: paperwork to acknowledge serial number for my new barrel has taken 3 months. But I am told it should arrive this week. My very patient RFD will finally be able to get the barrel out of his armoury.

Circling back to the Gunex vs Ballistol experiment I started all those months ago, the result is definitely a win for Gunex. The Ballistol section of the test piece now shows uniform surface rust and the Ballistol marker pen label is gone. The Gunex side remains intact :

View attachment 219308

Yep, no wonder. Ballistol emusifies with water. For this very reason it is so good for cleaning barrels and removing water but an absolute failure at rust protection for anything beyond absolute short-term.