Iosso Bore Paste

[skiutah02]

Have asked some good questions in the past (I hope), but now its time to potentially ask a "dumb" one.

Have never used any type of paste bore cleaner before.

At my last match, I was talking to a fellow shooter whose opinion I value. The topic of cleaning barrels came up and glaze carbon. He asked how I clean my barrel and I told him. He indicated that unless I am using a bore paste, I am not removing glazed carbon from my barrel and that might be contributing to some recent load "issues" I am observing.

So before I did something stupid to my current match barrel that is shooting pretty well and has nearly a match a week coming up over the next 7 weeks, I took out a similar barrel that I had bought from an AS member. I had cleaned the barrel well when I received it using "my" method of cleaning (CLR and Bore-Tech Cu remover), then sent about 30 rounds down the tube before taking it off my action to start another build (you know how it goes).

So I take a nylon brush, wrapped it with a patch and placed a decent dab of Iosso paste on my finger and worked it around the brush/patch to give a thin coat on the patch. I then inserted into the chamber and bore and short-stroked the entire length of the barrel (as was suggested my by acquaintance). Even though I had sent only a few dozen rounds downrange, the patch was jet black. I did this a few times and each time jet black patch. I then decided to remove the paste, etc by running 3-4 patches on a jag soaked with Montana X-treme Bore solvent.

I then decided to clean the barrel per my normal routine (CLR, Cu+2). After that I though to my self, "now that's clean!" Figured now I'd try the Iosso paste again. To my surprise, still coming out jet black and seems like no end in sight. So now my question(s):

Is this normal? Am I damaging the barrel and jet black is the remnants of my lands...? I suspect that you can "overclean"/erode a barrel using too abrasive a cleaner and too vigorous methods, so what does one look for? Or is this just the carbon (glazed and unburned powder) from many past rounds now just getting removed.

Looking for advise from bore paste gurus.

Thanks, Drew

 

[letronshootit]

An interesting read on 7mm.com from Australia, article called Death of a Barrel. Written by F-class shooter

 

[gotcha]

The black residue you're getting on the patches is normal for JB's. Much like the black residue you'd see when polishing aluminum. I've heard that Iosso didn't produce black patches??? So I have something to learn here also. Anyone out there that has used both and could provide a comparison regarding black patches ??

 

[skiutah02]

Thanks for all the responses so far. I did just read the "Death of a Barrel" article. Definitely food for thought, although I'm using a nylon brush and a proper (rotating) cleaning rod. Does seem to indicate that you can get overly aggressive with bore pastes, regardless of manufacturer, so I'll be careful. A kind gentleman mentioned that the black color is mentioned in Iosso's instructions ("manual, we don't need no stinkin' manual" - my bad). Also a reminder to oil the bore before the paste. Can't honestly remember if I did that, oops. Learning some stuff, so feeling good.

Drew

 

[TimP]

Cleaning you barrel bore with either JB or Iosso will produce black patches dirty or not. I just started using the Iosso product recently. I have been using JB for quite a few years. Not sure but it seems Iosso is a little more aggressive. With either one use sparingly.

 

[BoydAllen]

Do know someone with a bore scope? If you do, that is the best way to develop a cleaning method. There are generally two kinds of powder fouling, that start out as the same thing, the powder fouling that a brush, solvent, and patches will remove. In the back half of the barrel, this powder fouling can become something that the above mentioned products will not remove. One of the common terms for this fouling is carbon, or hard carbon fouling. It is an aggregation of powder fouling that has been made much harder, by the pressure and heat of combustion, and it requires careful use of an abrasive to remove.

There are significant variables, such as the kind of powder, the caliber to case volume ratio, and probably the peak pressure of the load. Some of this is experience, some guesswork.

First of all, before you "fix" something, it is a good idea to determine if it is "broke", and then after the procedure is done, if it is "fixed". This is where the bore scope comes in. Without one, we are guessing. Some powders do not require abrasives. Some do. Examples in the short range benchrest world, would be VV 133 which does not, and some of the other powders like surplus 8208, and LT32 that do.

There is another issue that comes into the use of abrasives. Any barrel maker will tell you that the reason that he does not put a mirror finish on the inside of his barrels is because to do so, would cause a jacket fouling problem that no amount of break in would fix. Abrasive cleaners in common use, particularly IOSSO (which I favor) can polish the interior of a barrel, which in itself can cause a problem. This is why it is important to use it only in the part of the barrel (back half to third) where hard carbon normally shows up, and only enough to solve the problem, no more. I prefer the softest black nylon bore brushes for this chore, loaded directly with IOSSO, with no patch, short stroked only in the problem area, which coincidentally is where bullet velocity is the lowest, and for that reason the least likely to pick up jacket fouling from an over polished bore. By learning how often to use an abrasive, and how much to use it when you do, as well as where the problem is, and is not in your barrel, you can do your barrel the most good with the least risk of messing something up, that would be difficult to remedy. Again, a bore scope is very useful for all of this.

 

[afrench]

the black you see is steel from your bore.

iosso and like products are great when used properly. i will clean my barrel normally then put a small dab of iosso on a patch, work it in with short strokes for the first 8" or so then push it out. (maybe 10 strokes total)... but that's just what i do.

if you work it in more than that, you are most likely removing excessive amounts of metal, not just the fouling.

no reason to do it more than once per cleaning. you can get the bore too polished and that can cause accuracy problems.

 

[Syncrowave]

First of all, before you "fix" something, it is a good idea to determine if it is "broke", and then after the procedure is done, if it is "fixed". This is where the bore scope comes in.

I would argue that this is where the target, not the borescope, comes in.

If the rifle shoots, I couldn't care less what the bore looks like and honestly would rather not know. If it ain't broke, I'd rather not open a new can of worms and possibly lose confidence in my gun in my personal headspace.

YMMV...

 

[jnyfeler]

An interesting read on 7mm.com from Australia, article called Death of a Barrel. Written by F-class shooter

Link? I don't find a website at www.7mm.com.

Jeff

 

[Dgd6mm]

I use Iosso bore paste. I polish the throat and bore every 200 to 300 rounds in my 6mms Competition Match barrels. I polish as Joe does and it works for me. I have borescoped before and after. My Tactical rifle shoots .4 moa at 600 yards after 3900 rounds down the barrel. I have not changed seating depth or altered the load. When this barrel gives up it will not be because of over polishing.

 

[lpreddick]

i call the hard to remove carbon residue "baked on carbon". i asked my gunsmith 15 yrs ago why jb always came out as black patches and he said "that's some of your barrel". a bronze brush with your favorite solvent will get this baked on stuff out, but will take quite awhile if the bore has been cleaned only with patches. took me days with one gun and it now shoots as it once did. some barrels may not copper but they all will develop this hard carbon layer even with "clean burning" powders.

 

[BoydAllen]

My experience has been that with 133 that I have not developed hard carbon. Other powders have not shared this distinction. This has been with several barrels, over a number of years, with borescope examination. Also, friend who were fighting accuracy issues (shooting different powders), had cleaned to white patches with brush, solvent and patches. We discovered the problem with a scope, and did a little work with IOSSO and removed it. A brush won't touch the really hard stuff. If you have never spent much time using a bore scope, there is some education that awaits you.

 

[CaptainMal]

Trashed a couple hundred Lapua cases in my Dasher earlier this year with carbon fouling issues in front of the chamber. Cleaned regularly and thought I cleaned well with a variety of solvents and sometimes JB. Well, after quite a mess, a friend borescoped the barrel. Said it was the worst carbon fouling he ever saw.

Still doubted as I always clean long and hard. Well Iosso and lots of C-4 Carbon Cleaner made it a shooter again. Lost a lot of cases to high pressure that blew the primer pockets open in just a single shot. Replaced the bolt head and firing pin. Waiting for a new Krieger barrel to come but for now - the old barrel is back to shooting and shooting well thanks to Iosso and C-4.

They are both now part of my regular "diet" with C-4 getting a lot of usage on many of my other guns.

 

[BoydAllen]

I am curious about the role of C-4 in your regimen. If you needed IOSSO (which I certainly believe to be true), and given that IOSSO will remove hard carbon, why bother with another product for this situation? Is it that you think that regular use prevents carbon buildup? Is this backed up by borescope observations? The reason that I ask is that while I know that in many cases the use of abrasive cleaners is a necessary evil, anything that can reduce the need for them is a good thing. Also, what powder do you use in your Dasher?

 

[hmcsr]

Jeff,

Try this: http://www.7mm.com.au/death-barrel/

 

[dkhunt14]

Boyd my buddy uses C4 in his dasher and he said it is the only thing that he found to remove the hard carbon from his barrels. Verified with borescope. Matt

 

[BoydAllen]

I may have to try some. Thanks for the reference, especially since it is backed up with a borescope.