Today it is a very common belief that while most ammunition will not cause direct corroding of rifle barrels, they do not have to be cleaned or oiled at all!
This is not, however, true. Besides corrosion, many other things can and will occur inside the rifle barrel, if not cared for properly.
During firing, every bullet leaves some metal residue onto the steel surface of the barrel. When more and more shots are fired, this amount of metal fouling will increase.
The bullet is driven down the barrel by high-pressure gas: generated by burning solid propellant (powder). This also gives, momentarily, a very high temperature. However, some solid particles of powder, and particles contained in the priming mixture, will remain on the surface of the barrel after each shot. These are partially pressed into the barrel steel, when squeezed by the next fired bullet. This is called powder residue fouling.
This phenomenon is amplified with fast and powerful cartridges. If a “Magnum” shooter wishes to get the best performance and accuracy from his/her rifle, cleaning and care maintenance is absolutely necessary. This can be readily demonstrated while shooting accurate loads form a bench rifle, and seeing how groups get wider and wider when the barrel gets dirtier.
This will happen with all barrels: even stainless steel barrels, which thus have to be cleaned at certain intervals too.
For proper cleaning, a good and solid steel cleaning rod must be used. Also a bore-guide, which helps to start the cleaning rod right from the centre of the barrel from the chamber end, is useful. Use only high-grade bronze brushes.
There are several different types of bore cleaners. Clean, pure ammonia will cause stress corrosion cracking, and is not a recommended chemical to be used – ever.
However, there are several bore cleaners which do have mild ammonia content; but they also contain many other chemicals that will not cause any harm to the barrels. There are also some bore cleaners that do not contain ammonia, but often have chlorinated hydrocarbons as ingredients.
Always follow the manufacturers instructions, and do not mix two or more different kinds of cleaners! This could form a corrosive chemical mixture, and damage the barrel.
Some of the most common chemical bore cleaners are: Shooter Choice, Barnes CR-10, Birchwood Casey’s Super Strength Bore Cleaner, Hoppes No.9 or Benchrest, RIG 44 Super Bore Cleaner, Forrest Professional Super Bore Cleaner, Kleen-Bore No.10 Solvent, etc..
There are also mechanical bore cleaning pastes like Gold Medallion Remcleaner, and JB Bore Cleaner (highly recommended). These need a very good, and comparatively tight cleaning patch, wrapped over a bore brush that is a bit smaller than that of the actual bore diameter. These will not harm the bore, and will clean off all the powder and metal residues. Once again, make sure you follow the manufacturers instructions.
When these cleaners act chemically or mechanically on the fouling, quite dirty green, blue or black patches will come out of the barrel. Finally, when the inside of the barrel is clean, there should be not dirt or metal residue visible on tight patches pushed through the barrel.
If one does not intend to shoot the rifle soon, a light coating of cleaning preserving oil, or rust preventative, should be wiped into the bore.
CLEAN BARRELS SHOOT BETTER, AND WILL LAST MUCH LONGER.
When the barrel is clean, and has a coating of preserving gun oil, a clean dry patch should be pushed through it before shooting: otherwise damage could be caused by excessive pressure. Note – a clean barrel may not shoot the first bullet to exactly the same group as the next bullets. This is normal, because the friction inside the barrel will change after the first, or a few shots.
All loads are not the same. There may be considerable differences both in the point of impact and accuracy (size of groups), from one brand of ammunition to the other.
All Sako and Tikka rifles have been tested at the factory for accuracy and proper functioning before packing. All rifles are protected with preserving oil before dispatch.
Coated bullets have recently appeared on the market. Various different coatings containing Teflon, moly-disulphide, etc. are used. These will all change the friction in the barrel compared to a similar uncoated bullet. Thus barrel time and muzzle velocity will change. Further, it will take several shots with a coated bullet to “neutralise” conditions within the barrel. This means that shooting just a few bullets of a certain coating type will not actually reveal anything. Maybe only poor accuracy will result. One has to make a longer series of shooting with these new bullets, to find out if they shoot well in your particular rifle.
Further to the above, a situation will arise when pitting can occur, mainly towards the muzzle end of the barrel when: A) the rifle is stored after use in wet condition, and B) the rifle is stored uncleaned in humid areas. This can happen even if only one or two shots have been fired. The advice, therefore, must be: clean the barrel after every use.
.22 Long Rifle rimfire rifles do not need cleaning as much as the centrefire rifles. But the differences in .22 LR ammunition can be considered large. Changing from one brand or load to another may cause temporary inaccuracy. This may take ten, twenty or even more shots, before the situation inside the barrel will settle to a level which remains the same from shot to shot, so maintaining groups.