The death of a good barrel from Bartlein point of view

[ecomeat]

What if he had JB Borepaste or similar stuck in the grooves of the rifling ? when you fired the .284 projectlie it would gather up the paste like a wave infront of it at 50000 psi and shove it down the barrel ? just an idea

Andrew,
That theory is certainly plausible, regarding the way that a projectile might gather a wave of paste in front of it , but the thing is with this, that it starts just in front of the chamber, and then every land is affected for 100% of its surface, all the way to the muzzle.
A little bit of paste might get left behind accidently once or twice by someone without a borescope, but I really, honestly do use my Hawkeye and check it every single time I clean.
Tony

[macguru]

I have an idea, dont clean the inside of cases at all, just wipe them

only use hoppes 9 , most of the time
remove carbon with paste or brush every 500 rounds

[AlanF]

What if he had JB Borepaste or similar stuck in the grooves of the rifling ? when you fired the .284 projectlie it would gather up the paste like a wave infront of it at 50000 psi and shove it down the barrel ? just an idea

Andrew,
That theory is certainly plausible, regarding the way that a projectile might gather a wave of paste in front of it , but the thing is with this, that it starts just in front of the chamber, and then every land is affected for 100% of its surface, all the way to the muzzle.
A little bit of paste might get left behind accidently once or twice by someone without a borescope, but I really, honestly do use my Hawkeye and check it every single time I clean.
Tony

Yes Tony, from what I saw, its a regular machined pattern all the way up the bore.

Alan

[Tim N]

If paste in front of a projectile caused the damage I'd think the whole bore should be marked, and if an area were to look polished after use wouldn't it be the top of the lands?
The grooves in the damaged barrel look like they were formed after the damage was done maybe compressing the gouges as the tool came through?Giving them a smooth finish? Not sure if that's the process, just what it looks like to me.
Bit like driving over cattle tracks in mud on a polaris just before you fall off

[DaveMc]

OK - whilst I understand from the gross view of one or two photos (and visually with naked eye) that it does look like machining marks - on closer observation I have to say I think that is almost definitely not the case (stopping just short of ruling it completely out)

1) As pointed out by Frank and I totally concur -Almost certainly this did not occur with reamer chatter or marks on cutting the initial bore diameter with drill, reaming and lapping. The grooves run down the side of the lands which can only occur after the rifling was cut. So this has to be ruled out almost conclusively

2) During rifling the machining rod is following the rifling - this is certainly not what happened - the gouges take a path that starts almost parallel with rifling then is "dragged into " rifling then goes down direction of bore then coming off the downslope wants to start tracking with rifling again. As Frank said this would have been observed in their QA, by the gunsmith (these are clearly visible) and by Tony in his "meticulous" borescoping regime - and I simply cannot see how a machining mark can do this on each and every gouge - it has to be more on an individual brush fibre or particle level.

3) Whilst I originally was thinking foreign matter (ss media, or other) I now also think this is unlikely. On contact with the rifling a small particle would want to track with rifling or go straight through - this is the other way around. It bends "into" the rifling not along it (e.g. by the increased pressure of a bent, shortened brass fibre of brush)

After thinking about this carefully I think the only thing that makes any sense to me (and only partly in that) are bristles on the brush (looks like a stainless steel or hard brush has been used). They are the only thing I can think of that would load up whilst trying to follow the rifling then have a force (pushing rod) that wants to follow bore direction as they are bent over (and stiffer) on top of lands and unload and start to track with rifling again. The canted lands could allow this to happen more than vertical sides to maddco rifling. If it was bore paste (hopefully not autosol or other diamond lapping pastes which I have seen some people use) on the brush fibres following the same track over and over then it might make some sense but it is something I think we would have to "regenerate" to prove and I am not 100% convinced myself.

One thing is for sure - nearly all barrel manufacturers are against abrasive paste use and probably for very good reason - there have been many reported issues with its use.

Anybody want to donate a 5R barrel and start lapping with KG on bronze brush???? - Maybe people are doing this and not getting an issue already (which is what I would expect if it is on the instructions) and maybe that in itself also rules this out

As I said

???????????????????????

- Cheap Chinese bronze brushes which are actually brass coated high tensile steel to save on copper use????

[saum2]

Tony,
You use your borescope quite a lot, I guess even running this problem barrel in at the start of its life. At what point (round count) did you first notice these marks?
Geoff

[ecomeat]

Dave,
Thanks again for your ongoing input. It is greatly valued.
I have only ever used ProShot bronze brushes bought from BRT by the dozen, and some from Sinclairs....again by the dozen. The Sinclair "nylon" brushes have seemed to be lower quality.....ends falling off easily...... But their bronze brushes have always seemed pretty good.
I do have, and use, the hard blue nylon brushes made by Iosso, but never with paste like JBs or the KG2. I use them when I use Sweets, Boretech etc for a follow up or for a change
Tony

[ecomeat]

Tony,
You use your borescope quite a lot, I guess even running this problem barrel in at the start of its life. At what point (round count) did you first notice these marks?
Geoff

Geoff,
After Sydney Queens last year, and before ACT Queens. I won't try and count round numbers till I get home from hospital and can check for certain. But the changes started to happen slowly and were first noticed not long after Sydney
It is something that you really don't want to admit to yourself is happening.All new barrels change in appearance as they break in/wear in and you see the regular changes thru the borescope.
I could have....should have...won the Sydney Queens with it, so it was working superbly at that stage. Bloody Roderick beat me on X's ! But that in itself is a testament to how good it shot.
It was a slow gradual degradation after that.
I unscrewed t for ages, but put it back in for the ACT Queens....and subsequently had a momentous battle with Craig McGown to not finish last ! We ended up 20th or 23 rd or so out of 26, I think.
My drinking associates and I met long and hard into the night at Canberra, and decided it had to be my overprinting of the bullets.
In hindsight, we probably erred in our judgement !
I am a pain in the arse, meticulous Reloader , and also use a MagnetoSpeed a lot. Have shot OPMs with one attached. Checked my loads before NQRA Queens in Townsville and was horrified to see that my super reliable "pet load" had lost 95 fps. Only had time to play with a couple of charges to get 180 gr VLDs back to 2820 fps and had to load and run off and catch a plane.
I would guess that the damage was only 50% done before I went to Townsville.
So it degraded a LONG, LONG way over the course of the Townsville Queens. As Dave and Frank have both measured, it is now missing a lot of metal, so I assume it's sort of reached a point of no return.

[saum2]

Tony,
Ok so the barrel looked fine at the start, so a gradual degradation to the present appearance. Does that rule out machining/barrel making errors??
It appears that something has been going down it to cause the gouges. Has Frank tested the barrel steel for hardness etc?
I'm just going back to the start again which may assist you in remembering what you did if anything out of the normal with the barrel for it to end up the way it has which is quite weird.
Remember you've had 3 things go wrong now; shoulder, barrel and the leg, so the future is bright
cheers
Geoff

[jasmay]

I don't have to much to add, but I did go and have another read of the KG2 bottle, and I must say I get 2 things out of it.

1) it does say in cases if heavy fouling to use a brush, this makes sense to me but I think they should be more pacific about ONLY using a patch when polishing.

2) polishing/lapping with a brush makes little sense to me, would you polish your car with a stuff brush?

Now, I feel that what I am seeing is as a result of polishing with a brush using a cutting compound. I have had a bit to do with lapping different surfaces using different methods due to my trade, and one thing I can say is you can accentuate existing marks or grooves quite easily.

If the bore either from factory, or from another factor glt some light marks in it, using a brush coated with a polishing/lapping compound could possibly acctenuate those marks when te bristles follow them.

When your lapping/polishing your really need 100% surface contact to achieve good results, think of dipping your fingers in cutting compound and going at your car bonnet, it's not going to be pretty.

I don't think we will ever get to the bottom of this, but all the ideas discussed have certainly opened our eyes to taking more care with the procedures we use.

[Brad Y]

Coming from someone who uses JB/iosso on a nylon brush to remove carbon, wouldnt a patch not be as efficient? Of course patches are good if your trying to polish, but we are trying to remove carbon build up- especially from what I have seen in a borescope- out of the grooves not on top of the lands. Short of a button that perfectly matches the rifling to scrape it out, a brush is about as good as we can get. Ive never seen any damage from using iosso or JB but have seen damage from over use of short scrub without a boreguide. Basically one land gets polished out (usually 6 or 12 oclock in the chamber). I know its not generally looked upon as favourable by barrel makers, but its the best way I know of removing carbon. Cleaning when warm helps and so does TEC, but never 100% perfect. Though the KG solvent looks like it would be great to try, just cant get it here in WA it seems...

[Barry Davies]

What are you blaming Brad " the overuse of shortscrub " or the lack of a " boreguide "
Shortscrub has no abrasive what so ever, so it does not polish.
The lack of a boreguide will likely cause barrel wear with whatever you use as a solvent.

[RAVEN]

KG is finer than JB don’t know about losso

I never use KG polish on a brush except with a cleaning patch over it to make a tight slug

Tony could it have been hard carbon going down the bore under the bullet
Probably farfetched maybe that could have been the start and the extra polishing with abrasive on a brush over time exaggerated it.

Frank did mention not to use nickle plated brass for I guess that reason

I only use the KG2 occasionally 4 times a year maybe
A lot of barrels are worn out by overexuberant cleaning.

The lack of a boreguide will likely cause barrel wear with whatever you use as a solvent.

I agree with that Barry
RB

[Brad Y]

Barry, I never blamed anything. Just asked a question related to using an abrasive with a brush which has been spoken about already. OFF TOPIC- Barry, if short scrub had no abrasive, why was there a ball in the bottle to mix up the ingredient that settled to the bottom? It sure felt abrasive when rubbing it between my fingers. Are we talking about the same stuff?

EDIT- sorry I re read your question. Any bore cleaning without a good bore guide is a no no in my books, but using abrasive while not being able to control where the rod is going is what I was trying to refer to.

[Malcolm Hill]

Using polish with a bronze brush is the only way to remove carbon build up in the corner of the lands and grooves. Using a jag and cloth only ever polishes the top of the lands and at best the centre of the grooves. I clean numerous barrels and when needed use polish on a bronze brush (Kg 2 or JB- the Kg is easier to clean off the brush) and inspect all the time with a borescope. I have yet to evidence any damage to any barrel with this method. For all those that swear by a jag and cloth keep using it- every barrel I have ever inspected that owners use a jag in shows the same damage. All are damaged at the crown where people unwrap the cloth after it exits the muzzle and then drag the rod and jag back through the barrel. Ever wondered what the donk, donk , donk noise is as the jag goes back into the barrel. Yep it is the sound of damage to the bottom of the nice sharp edge of the crown. Don't knock the use of a bronze brush, even if it is returned back through the muzzle it does far less damage than a jag as it self centres in the bore as it re enters the muzzle.
Regards Malcolm.