The death of a good barrel from Bartlein point of view

[jasmay]

I wonder if the "Bronze Brushes" being used are indeed bronze and not a cheap arse brush made somewhere in china and are actually Stainless?

I cant see it being the tumbling media, although, at first this is what I thought, now looking more at peters photos, Tony would have had to have missed more than a couple, way to much damage IMO.

This combined with the fact Frank just pointed out about the rod not turning with the rifling due to its construction could make a bit of sense.

As for the chrome plating, Tony, don't you polish using KG2? that's stuff will make anything look like a mirror.

I don't think we'll ever get to the bottom of this, but the list of causes is narrowing.

Anyone think its worth considering some dodgy projectile jackets?

[DaveMc]

I think the only way to truly get to the bottom of it is to replicate the damage.
Pick the 2-3 most likely causes and start there.

As you say Jason I think we have eliminated a lot but until we can demonstrate it these theoretical answers are just that - theory

Is it worth doing this and getting to the true cause???? - Quite possibly. If indeed it is caused by a "common" cleaning method or tumbling media and more barrels are likely to suffer then it could well be worthwhile. At this stage there are only 2 though.

Does anyone have a worn out old 5 R barrel where throat is gone but last 20+ inches still look ok - Frank might have a access to a few.....

[Frank Green]

...AlanF thanks for posting the pictures and taking the time to cut the barrel sections etc...

I posted the pictures Frank, but Peter Smith, one of our foremost experts on these things, did all the work and authored the report.

BTW I hope you know that regardless of what people suspect has happened with this barrel, there are many of us very keen to have Bartleins available here in Australia. My Bartlein which was bought in the same order as the problem one, has just helped me to win the F-Open class in our premier event the National Queens Prize. It has now done 1200 rounds, and by the condition of the throat, has plenty more to come.

Alan

AlanF, Tell Peter Smith Thanks if he doesn't get on this forum at all!

Congrats on the win!

Again I go back to a earlier comment also....if you and some other shooters bought barrels at the same time and got them imported from Grizzly etc...if the barrels came out of the same run/order we made Grizzly (that's why I was trying to find out s/n's) and your barrel doesn't have the damage like Tony's then it cannot be from when the barrel was made.

If those barrels were all run at the same time meaning the same tooling etc...then there should be more than one barrel with the same damage.

Talk to you later, Frank

[Tim L]

I wonder if the "Bronze Brushes" being used are indeed bronze and not a cheap arse brush made somewhere in china and are actually Stainless?

I was just about to post something similar. I can't see a bronze brush being able to make those gouges, but a bronze coated steel one, that's a different story.
It's possible that with the bristles under no compression they would just brush (and polish) the grooves, but if the rod wasn't turning they would not like being rammed over the lands.
I vaguely remember a post saying the brushes were bought in bulk from the same supplier but is it possible that an odd one has slipped in there. Or, the usually dependable supplier has contaminated stock!??

Who want's to debunk this as a theory.
A patch wrapped round a steel brush, (this isn't a nice new shinny 7mm brush, it's the old worn one from ????) the patch (and undersized brush)actually assists the brush in riding the lands so it doesn't spin down the rifling. A few full length strokes (with polish, Iosso or JB???) The patch and polish do a lovely job on the groves, while the steel bristles tear up the lands.
I doubt it's going to happen in one session though, so where's the brush?

[DaveMc]

We approached this theory earlier (see page 2) and do agree it sounds quite feasible.

[johnk]

Back a goodly time now (I recall it was prior to the 2006 trip to England) , I had a match rifle barrel borescoped (still don't have a Hawkeye myself) during an Aussie team practice & it was diagnosed with noticeable striations in the grooves even though it was a young (Kreiger) barrel. I was using a K & M stainless rod & Dewey guide & bronze brushes, bevelling the rod end as per Nev Madden's advice of yore. We were required to attend internationals with barrels less than 1000 rounds old. I recall pulling it & replacing it after returning from Bisley with an old favourite.

I must look around in my junk cupboard to see if I still have that tube. Maybe it's time to revisit.

[KHGS]

As you say Jason I think we have eliminated a lot but until we can demonstrate it these theoretical answers are just that - theory

There have been "theories" put forward that are not logical, these are eliminated. I still stand by my original statement of foreign object or objects, most likely we will never know what or how. It does not look like cleaning damage to me & it does not look like a manufacturing or steel fault to me either, however I say this without examination, so only my theory based on inadequate information & so final judgement is reserved.
Keith H.

[Tim N]

Hi All,
Frank- Thanks for your explanation of the rifling process.
I thought that the damage may have been done prior to the rifling process leaving the lands and damage exposed.
I see how your process would only leave the damage on the top of the lands and not down the sides.
My question is could the result be obtained with the button rifling process?
If so could the barrels in question be from someone else?

[Tim L]

As you say Jason I think we have eliminated a lot but until we can demonstrate it these theoretical answers are just that - theory

There have been "theories" put forward that are not logical, these are eliminated. I still stand by my original statement of foreign object or objects, most likely we will never know what or how. It does not look like cleaning damage to me & it does not look like a manufacturing or steel fault to me either, however I say this without examination, so only my theory based on inadequate information & so final judgement is reserved.
Keith H.

Unfortunately Keith, we are only ever going to arrive at the "most likely probable cause" even if replicated it doesn't "prove" that was what caused this. The root cause analysis process attempts to gather all the information possible then becomes a case of eliminating possibilities. Those theories which are left are then analysed for a best fit.

Currently, I think we sit with this not being a manufacturing error unless there is an explanation of how a complete failure of process (including QC) can be explained.
For me personally, foreign matter blasting down the barrel must be accompanied by an explanation of how it defies the laws of physics and stays out of the grooves.
With those two main causes currently sidelined I'm left with the manual destruction of the barrel as the only remaining contender.
Feel free to disagree with this, but for me, any theory must account for wear to both the grooves and the lands as well as polish the grooves, whilst gouging the lands.

@ Peter, you've probably had the best view of this damage to date. Could you make a call on whether these gouges are uni or bi directional?

[AlanF]

I think the only way to truly get to the bottom of it is to replicate the damage.....Does anyone have a worn out old 5 R barrel...

Not yet, but if you can wait for a bit ....

[aaronraad]

So where are we at and is Tony up and about?

From what I can gather (please comment/edit or expand):

1. something significantly harder than the surface of the lands and being forced through with significant pressure
2. with a low wear rate and leaves little or no trace of adhesion/gauling/snail trail etc.
3. something that passes through less than the groove diameter
4. something that has a contact point/edge less than 0.005"(0.13mm)
5. something that Tony has in his equipment list and possibly something(s) Tony uses uniquely in combination with (an)other item(s)

I'm thinking contaminated bore paste or overzealous use of bore paste. It's possibly only 12 dozen particles of something like 80 to 100 grit that made it's way onto the patch.

[Tim L]

So where are we at and is Tony up and about?

From what I can gather (please comment/edit or expand):

1. something significantly harder than the surface of the lands and being forced through with significant pressure
2. with a low wear rate and leaves little or no trace of adhesion/gauling/snail trail etc.
3. something that passes through less than the groove diameter
4. something that has a contact point/edge less than 0.005"(0.13mm)
5. something that Tony has in his equipment list and possibly something(s) Tony uses uniquely in combination with (an)other item(s)

I would refine the first two

* something harder than the surface of the lands was forced through.
* with a significant wear rate (unless I'm reading it wrong, as well as the damage to the lands, this barrel has worn out prematurely?) and leaves little or no trace of adhesion/gauling/snail trail etc
*something that passes through less than the groove diameter
*something that Tony has in his equipment list and possibly something(s) Tony uses uniquely in combination with (an)other item(s)

Is the copper trace that is only seen present on the right hand side of the lands a clue. Not so much that it's there, but that it doesn't appear to be present on the left side??

[aaronraad]

So where are we at and is Tony up and about?

From what I can gather (please comment/edit or expand):

1. something significantly harder than the surface of the lands and being forced through with significant pressure
2. with a low wear rate and leaves little or no trace of adhesion/gauling/snail trail etc.
3. something that passes through less than the groove diameter
4. something that has a contact point/edge less than 0.005"(0.13mm)
5. something that Tony has in his equipment list and possibly something(s) Tony uses uniquely in combination with (an)other item(s)

I would refine the first two

* something harder than the surface of the lands was forced through.
* with a significant wear rate (unless I'm reading it wrong, as well as the damage to the lands, this barrel has worn out prematurely?) and leaves little or no trace of adhesion/gauling/snail trail etc
*something that passes through less than the groove diameter
*something that Tony has in his equipment list and possibly something(s) Tony uses uniquely in combination with (an)other item(s)

Is the copper trace that is only seen present on the right hand side of the lands a clue. Not so much that it's there, but that it doesn't appear to be present on the left side??

I figured it would have to be low wearing as the gouges seem to run from one side the lands to the other. They would probably keep going from muzzle to the crown if it didn't have to jump from one land to the other. I didn't notice any gouges starting in the middle of a land section. They all seem to start and finish at the edge.

Travelling in one direction or back and forth? No chatter marks visible in the grooves shown in the pictures but the helix angle seems to vary slightly?

[aaronraad]

Is the copper trace that is only seen present on the right hand side of the lands a clue. Not so much that it's there, but that it doesn't appear to be present on the left side??

I think the 'copper trace' on the rhs of the lands is a 'feature' of the 5R rifling. The gouges still look perfectly 'clean'?

[Tim L]

So where are we at and is Tony up and about?

From what I can gather (please comment/edit or expand):

1. something significantly harder than the surface of the lands and being forced through with significant pressure
2. with a low wear rate and leaves little or no trace of adhesion/gauling/snail trail etc.
3. something that passes through less than the groove diameter
4. something that has a contact point/edge less than 0.005"(0.13mm)
5. something that Tony has in his equipment list and possibly something(s) Tony uses uniquely in combination with (an)other item(s)

I would refine the first two

* something harder than the surface of the lands was forced through.
* with a significant wear rate (unless I'm reading it wrong, as well as the damage to the lands, this barrel has worn out prematurely?) and leaves little or no trace of adhesion/gauling/snail trail etc
*something that passes through less than the groove diameter
*something that Tony has in his equipment list and possibly something(s) Tony uses uniquely in combination with (an)other item(s)

Is the copper trace that is only seen present on the right hand side of the lands a clue. Not so much that it's there, but that it doesn't appear to be present on the left side??

I figured it would have to be low wearing as the gouges seem to run from one side the lands to the other. They would probably keep going from muzzle to the crown if it didn't have to jump from one land to the other. I didn't notice any gouges starting in the middle of a land section. They all seem to start and finish at the edge.

Travelling in one direction or back and forth? No chatter marks visible in the grooves shown in the pictures but the helix angle seems to vary slightly?

I'm looking at the gouges and the wear as being caused by separate issues. I maybe wrong there, but there are no gouges in the grooves yet the grooves are also worn???
The wear rate, given the age/use of the barrel seems rapid.
Something has "worn" the barrel (groves and lands) AND gouged the lands. There is also the mention of "highly polished" grooves.
Try as I might to come up with an alternative, and undersized steel brush and polishing media is all I can come up with that ticks all those boxes.

That's not to say they are the correct boxes to tick, but it's where I end up reading the information that we have.

If we can confirm the gouges are bi directional, then it would add weight to that theory. It would also kill off the possibility that this was something fired down the barrel.


Should we not "expect" copper to be trying to fill those gouges??

Does the lack of copper anywhere but on "the far side" of the lands indicate it has been removed?