Educational Zone #48 – Cleaning a Rifle Barrel

Today, we will discuss how to properly clean a high power rifle barrel.

Just a word before we start… Recent installments about how to clean other firearms caused some confusion.

I am demonstrating one way to clean a rifle barrel. This is the way I do it. It is not the only way, it is just one way. 
It works very well for me and has for many years. 

I will be cleaning a Mosin Nagant M-44. It is a C&R rifle, with a “gray” bore, meaning that it was shot sometime in the past with corrosive ammo and it wasn’t cleaned properly.

That made the rifling a little “rough”, or slightly pitted. It still shoots fine, but it is a little harder to clean, as the rough bore picks up more fouling.

To see how to properly do a field cleaning of the bore immediately after shooting corrosive ammo, look at this.

We will now discuss what to do after we get home from the range.

Rifle barrels are more difficult to clean than most pistol barrels. The main reason is that rifles work at much higher pressures and shoot copper jacketed bullets at high velocity. This can cause some of the bullet metal to be “scraped” off and deposited on the rifling. This fouling must be removed and requires some special procedures.

We start by making sure the rifle is empty of cartridges and then removing the bolt.

I spray the bolt with solvent (WD-40) and set it aside until later.

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I use a coated Dewey Bore Rod in the appropriate caliber and I also use a patch-piercing jag, both in .30 caliber.

I like to use fairly tight fitting patch, and for this caliber I use a 2 inch round patch.

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The fouling is best removed by using a little chemical help.

I use a mixture I learned about from Precision Shooting Magazine, that many top benchrest shooters use.

It is a half & half mixture of Kroil and Shooter’s Choice.

I keep it in a small plastic bottle for ease of application.

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I place the patch on the jag and then apply the mixture on the patch.

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I run this through the bore from the chamber end.

This is especially important in high quality rifles, so as not to damage the crown on the breach end of the barrel.

On this rifle it isn’t quite as important, but I simply have a habit of cleaning from the chamber and always do it that way if possible.

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I wet the bore and then change to a bronze bore brush in the appropriate caliber.

The Mosin has a .310 to .312 bore, but they are usually worn, so I use a .35 caliber bore brush to get a tight fit.

I apply some Kroil/Shooter’s Choice to the brush and then push it through the bore, 6 to 8 strokes, both ways.

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I then run another soaked patch through and it will push out a bunch of black nasty stuff.

This is a mixture of powder fouling and copper fouling from the jacketed bullets.

I then push another soaked patch through the bore and set the rifle aside for 30 minutes or longer.

This will allow the solution to chemically dissolve the copper fouling in the bore.

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I take this time to clean the bolt.

I scrub it with solvent and an old toothbrush, being sure to clean the bolt face and under the extractor.

I spray more solvent on it to wash off the crud, and then use high pressure air to blow it all clean and dry.

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After letting the solution “work” a while, I wet another patch and push it down the bore.

You will notice the green color of the stuff pushed out of the bore.

This is evidence that the solution is dissolving the copper.

I then use another soaked patch and can do the whole procedure again, if desired.

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Some ask, “How many times do you have to do this?”

The answer is different for different rifles. A new rifle, with an excellent bore will probably be clean enough after one cycle of the procedure. A “rough” bore may benefit from more than one cycle. Even a new and excellent bore may require more than one cycle, if it hasn’t been properly cleaned in a long while.

I once helped a friend clean a .25-06 Remington hunting rifle that he had bought at a gun show. The bore was filthy and it shot “patterns” of about 6 to 8 inches, instead of “groups”.

We cleaned the rifle in this manner several times before it cleaned up properly. He then took it to the range and it shot into 1 1/2 inches at 100 yards. A clear case of poor shooting because of a filthy bore.

But keep in mind that on an old C&R rifle like this one, you could do this procedure dozens of times and every time you would get black stuff after the brush scrubbing and get green patches after letting it soak.

The truth is that after a while on these old C&R rifles with rough bores, you are just removing more and more rifling from the bore. It will never be 100% perfect again, no matter how much you scrub it. And excessive scrubbing does more harm than good.

I usually do only one cycle of cleaning on these old rifles.

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After the bore is clean, I spray solvent into the locking lug area and also wash out the solution from the bore.

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I then blow it down the bore with air.

Then a couple of dry patches until it is completely dry.

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I then apply some rust preventative oil to a patch.

I use a product called “2 N 1″ oil made by “Rock N Roll Lubrication Company”.

It is a very light oil that penetrates and serves as a rust preventative.

A couple of passes with the rust preventative and the bore is finished.

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I then lubricate the bolt with Birchwood Casey Synthetic Oil and replace it in the rifle.

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I then do something that many may consider unnecessary.

I rest the rifle, muzzle down, on an old tee shirt, overnight for 24 hours, to allow any oils to drain out of the barrel without draining back into the action and possibly the wood of the stock.

Usually there is only a slight indication of any oil, but it doesn’t cost anything to be sure. 

Conclusions:
All this procedure takes a little time, but you will be rewarded with a clean, bright bore and the best accuracy that is possible with the rifle. 

Next time… Cleaning an AR15 rifle.