When a clean barrel isn't, and one way to clean it

[big5ifty]

I've got about 300 rounds through a target rifle. After every session, I would alternate nylon bushes with Boretech Eliminator and Ballistol, patching till clean, and repeat three times.

This rifle shoots a particular monolithic very well, and I wanted to understand why.

So I did a sulphur cast of the muzzle area, and measured groove diameter. According to that the bore is so far out of spec it should have been scrapped.

I then used a soft lead plug tapped about three inches into the muzzle, then tapped out. I got he same measurement.

I repeated the lead slug from the muzzle, this time all the way to the chamber. The slug was tight to about one third of the barrel length from the muzzle, then suddenly it became loose and pushed through much easier to the chamber. That means I was measuring buildup in the barrel grooves, not groove size.

Wet patches of Boretech, leaving it in the barrel for hours, but the dry patches came out clean. The borescope was showing a shiny inside, which on closer inspection and more with thought started looking like polished carbon buildup.

Youtube showed one referral to UltimateReloader using penetrating oil with success. I drove down the hardware and picked up a tin of Q5.

I have a lot of nylon brushes, and only one very old bronze brush that fits my caliber. Using Q5 and a nylon brush made the first patch go black, but subsequent passes with Q5 and the nylon brush didn't do much. I then used the Q5 and the bronze brush. Jackpot. Every clean with the bronze brush freed up enough carbon to produce pitch black patches that looked like they were dabbed with soot.

I just ordered bronze brushes for my target rifles. I won't use nylon brushes to clean carbon again. And I want another tin of Q5.

[Ds J]

I had a similar experience, even though it was not as scientific as yours.

I received the old 303 and cleaned it properly, then left it in the safe with an oiled barrel. (The chances are good that the rifle wasn't fired for +-50 years!).

When I got to the range some weeks later I pushed a patch through it to remove the oil, and it came out black as sin. The third patch was clean enough that I started shooting. Maybe I need some Q5 as well.

[oafpatroll]

I've also had limited success with nylon brushes. Luckily I haven't needed anything more expensive than my home brew South Africanised Ed's Red for carbon buildup in any of my guns yet. It's equal parts paraffin, turps, acetone and ATF. I add a bit of lanolin grease to the bottle I use for general cleaning as a rust preventative.   

[janfred]

I never quite understood why shooters have this aversion to using bronze brushes.

It works much faster and better than nylon or patches.

[oafpatroll]

I never quite understood why shooters have this aversion to using bronze brushes.

It works much faster and better than nylon or patches.

Same here. If you can blast a copper alloy jacketed bullet down a tube designed for that purpose what damage could dragging a lubricated bronze brush down the same tube?   

[Treeman]

I never quite understood why shooters have this aversion to using bronze brushes.

It works much faster and better than nylon or patches.

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I too have only just recently started using bronze brushes again, and at that only every 5-6 th cleaning. I do not know the reason, but I have a aversion to the bronze brushes, likely unfounded.

[Treeman]

When one has a bad barrel like mentioned, a bronze or copper pot scourer wrapped around a bronze brush is the answer, just test the pot scourer with a magnet and buy the more costly version from a better shop - the kind that sells high end pots and pans.

Warm the barrel by blowing a hair dryer through it till its hot to touch and then pour some hot as can be made safely ATF down barrel slowly with end plugged (careful now). The hot ATF just seems to get "in there" better.Then scrub.

People shake their heads when I tackle a problem barrel. I tend to get a bit silly, but so far it works. I use Bicarb, Coke, ATF, Peroxide, Ammonia, Citrus soap, brake cleaner, acetone and mineral turps and some things I have forgotten. I wash barrel with acetone or benzine between each attempt so that next attack is not dulled by oil from previous attack. I do all the different approaches because I think each one is another angle of attack and does its bit, the carbon is not just carbon,its a few other minerals, chemicals and metals which each need their own silver bullet. Refreshed applications of Coke can be left in barrel for long, peroxide, ammonia  not so long and must be cleaned out properly. ATF - Eds Red and Mineral Turps over night is good. Biodiesel is also a very good cleaner and soaker. All items mentioned if used with correct cautions have their place in my arsonal, all are used interspersed with the use of commercial products, and all in all it sometimes takes days to get a barrel cleaned. I honestly thought I may be ruining my 1918 .303 Brit barrel, I scrubbed and swabbed it for days before some marks and thingees in the barrel were gone, it went from hitting a A4 page group to a quarter inch group shooter with some stock work included.

[big5ifty]

I think that the advocates of nylon brushes never had to get a barrel clean, or else they don't have a borescope to see what a kak job nylon brushes actually do.

A nylon brush is good for coating the bore with copper remover and such chemicals that would affect a bronze brush.

[Ds J]

I have read or heard somewhere that the notion/aversion against bronze brushes is because folks believe that it would scratch the barrel.

Phosphor-bronze is believed to be harder than steel because it is used in cutting diamonds. This means that people don't understand the process of cutting diamonds.

[big5ifty]

Saying a bronze brush hurts the barrel is like saying you can take a hack-saw blade made from copper and hand-cut a mild steel bar with it.

Yes, they use bronze to cut diamond, but you can also use water to cut steel. Doesn't mean getting the barrel wet is going to melt it.

[oafpatroll]

Saying a bronze brush hurts the barrel is like saying you can take a hack-saw blade made from copper and hand-cut a mild steel bar with it.

Yes, they use bronze to cut diamond, but you can also use water to cut steel. Doesn't mean getting the barrel wet is going to melt it.

I think they mistake the 'carrier' or 'matrix' for the abrasive in those analogies.

[janfred]

Not sure where that myth started.

The hardest phosphor-bronze at 85 Rockwell C (3 Rockwell B) is softer than the softest barrel steel at 102 Rockwell C (25 Rockwell B).

https://www.chemistrylearner.com/phosphor-bronze.html

https://www.nrafamily.org/content/what-is-the-best-gun-barrel-material/

https://pgisteel.com/hardness-conversion-chart/

Bronze has been specifically selected as it is harder than gilding metal and copper but softer than steel. The idea is to be able to mechanically remove the lead,  copper and carbon from barrels without scratching the steel.

[Treeman]

I have often wondered - If I were to freeze a barrel, will the different materials in barrel not come off due to the different shrink, contraction rates. Many glues just separate if frozen and many joints come loose, so ?

[big5ifty]

Interesting idea. Steam is one of the methods to remove carbon buildup off metal, the metal expands more than the carbon, so it breaks the adhesion.

[Treeman]

Interesting idea. Steam is one of the methods to remove carbon buildup off metal, the metal expands more than the carbon, so it breaks the adhesion.

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Yes same idea.

If you ever need to use a grid and yours is not around, but you find a old scrappy one lying somewhere or the camp site provided horror. Put that grid in the fire and glow it then dump it in a pond or stream, what ever. Every thing other than the bare metal just jumps of the bare metal, rust especially. When you do it in a bird bath or cement water retainer it is absolutely amazing to see the pile of crud that sinks to the bottom.