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Rifle Bore Cleaning

The subject of cleaning a rifle barrel is quite complex. There are an number of questions that are frequently asked with regards to barrel cleaning.

1. How should I clean a barrel?

2. When should I clean the barrel?

3. How often should I clean a barrel?

4. How many shots should I fire between barrel cleans?

5. How clean does a barrel need to be?

6. How do I run in a barrel and is it necessary?

I will attempt to answer these and other questions in this article, but before I start it must be noted that every rifle is different and different procedures may be required for individual rifles.

To begin with lets look at a new Stainless Steel Tikka T3 rifle. This model of rifle is very popular in Australia and generally offers excellent accuracy right out of the box. The photo above is of the muzzle crown on a Tikka T3 in .338WM. It has had 10 rounds fired by the owner and has been cleaned 5 times.

The first clean was before the first shot was fired, to clean out the residue from the factory proof firings. This removed both oil, carbon and copper.  It was then cleaned after the first, second a fourth shot. Each time until no copper could be seen on the patches or at the muzzle.

Finally it was given a light clean just enough to take the photo above to show the bright copper streaks on the rifling lands. Even though the Tikka barrel is quite smooth on the inside, large amounts of copper have stuck to the lands. This seems to be common with a lot of new rifles and it takes some time before this stops happening. Sometimes with a new hammer forged stainless barrel, copper streaks can be difficult to remove from the smooth surface of the lands.

In contrast to the photo above, the photo to the left is of a Chromolly, .30-06 barrel made by Savage Steven's using a different barrel making method.

Now this brand of rifle is very cheap and sells in Australia at the moment, new for $399 if you can still find one.

As you can see from the photo, the bore is very rough and the machining marks from the barrel making process are very evident.

Now you would think that this barrel with its rough bore would foul up very quickly and be quite hard to clean. However this barrel has fired about 500 shots in total and is actually plenty accurate enough for hunting purposes..

These very fine machining groves at right angles to the lands tend to fill with fouling and have no effect on accuracy. 

Cleaning out all the fouling from these micro groves is pointless as the projectile rides on top of these groves. However it is important to keep the surface above these groves clean.

I just cleaned this barrel prior to the photo being taken and it had about 50 shots down the tube since its previous clean. Cleaning out all the fouling from these micro groves might actually make the barrel foul badly next time it is shot.

This is what makes barrel cleaning so unpredictable. You just never know how a barrel will behave until it has settled down and fired a number of shots.

Most barrels settle down after between 20 and 80 shots. Accuracy improves and the amount of "hard to remove" fouling becomes less. 

The photo below right show another image of the smooth Tikka barrel insides with its streaks of copper. The photo below left is of a hand lapped "Hart" barrel in .308 calibre that has just been cleaned.

The "Hart" barrel has just fired well over 1000 rounds in total and it has been 350 rounds between its last clean. It is a competition rifle and is very accurate.

When the Hart barrel was cleaned it came up clean easily and required very little work. Almost no copper fouling was evident. This shows that it is not always necessary to clean a rifle barrel that often. You need to get to know your barrel and discover how often it needs to be cleaned.

If you clean your barrel more often than necessary then you could actually be doing more harm than good. The process of cleaning a barrel can damage the barrel if not done right.

Corrosion protection is different to cleaning a barrel to remove fouling. Even stainless barrels can rust depending on the grade of stainless steel used. Tikka T3 Barrels a such barrels and should be protected when stored against rust.

Spare barrels should also be protected against rust. I had a spare Pac-Nor barrel that was sitting in the safe for a couple of months. When I pullet it out for inspection, I could see slight corrosion marks from finger prints on the outside of the stainless steel barrel. This was a warning to me to get some oil into that barrel, otherwise when it came time to use it there may have been rust pitting inside the bore and no one wants a new barrel with a pitted bore.

Different barrels and different types of rifles will require a different number of shots between cleaning. You just need to work out for yourself what is best for your particular rifle. The important two things to consider are accuracy and how easy it is to clean.

A Benchrest rifle may require cleaning between every distance competed at. (say 14 to 24 rounds). A F-Class rifle may be cleaned at the end of the days shooting (Say 24 to 36 rounds). In both of these cases, fouling and sighter shots are fired before the scoring shots are fired, so clean bore shots are not a big issue. I have a .308 F-Class rifle that can easy go 350 rounds between cleans and is still very accurate and easy to clean.

A long range field rifle, used to shoot steel gongs etc, can go a long time between cleans. The best thing is to foul your clean barrel with a few shots, then shoot some groups. Use these groups as the base line accuracy of your rifle. Then shoot some groups after your rifle has had say 40 to 50 shots since its last clean. Then compare the group size. If it is still shooting bug holes then great. Clean your rifle and see how hard it is to clean. If it is still easy to clean then you can go for a longer run between cleans next time. Doing this will give you a "feel" for your rifle and when it needs cleaning.

I use a bronze brush to remove Carbon. Its important to keep Carbon build up under control. If Carbon is a problem you may "feel" it when you clean the barrel with a wet patch. The barrel will feel tighter in the area just in front of the chamber.

With a long range hunting rifle, the first shot must be on target, as you generally don't get sighter shots on game. So I always put three or four shots down the tube after I have cleaned the rifle and before I go hunting. I then hunt with the rifle for a few months before I clean it again.

It is quite common for the first few shots after cleaning your barrel, to hit low at long range.
This is the main reason I fire a few fouling shots with my LR hunting rifle prior to heading bush.
My .338 Edge will shoot about 1.5 moa low at 1000 yards on the first shot after a clean. After three shots it is back up to its normal POI.

I don't bother with much serious load development until a new barrel has about 70 rounds in total down the tube. That's when they seem to settle down and are properly run in. True load development can then take place.

I clean the barrel, then fire a few fouling shots. Let it cool properly then fire my first test group. The barrel is then left to cool again before shooting the second group. etc.
The number of groups I fire will depend on how the barrel cleans up during the running in process.
During the initial 70 shot run in period, I start of with three shot groups. These are handy to determine what load your rifle does not like.
After the run in period I fire 5 shot groups to work out what the rifle does like.
With the smaller calibres, .22, 6mm, 7mm, .308 etc, I fire 10 shot groups to work out which of the good loads is the best load. These groups may be shot during a local club match if conditions are suitable. With the big bangers, I do my final development with five shot groups, and a clean after four or five groups.

If the rifle gets wet, I always give it a thorough clean to avoid corrosion. I don't like to clean too often if it is not needed..


More to come

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