If every shooter who had an opinion on cleaning a barrel was laid end to end on the range at Bisley… they’d still never reach quite as far as a conclusion!
You see, there are two schools of thought when it comes to cleaning airgun bores – ‘do’ and ‘do not’.
The truth is, unlike firearms where a residue of carbon deposit can build up from burning powder, there’s no definitive ‘correct’ thought when it comes to scrubbing out your air rifle’s bore.
The biggest ‘deposit’ in an airgun’s rifling is lead from the pellet itself – although a springer that’s dieseling heavily can also chuck a whole load of unburned (and burned) lubricant down the tube.
While the latter needs cleaning out, the lining of lead in the barrel isn’t so much of a bad thing; it can only build up so far before being dragged away by successive pellets.
Indeed, there’s a good case for simply leaving an airgun barrel alone. Any ‘leading’ (as it’s called) reaches an equilibrium where it’s sheared off at the same rate as it’s deposited.
And if your rifle’s shooting fine, why meddle? The only time to seriously consider a clean-out is if your accuracy has gone off (for no explicable reason) and inspection of the bore shows it to be noticeably dirty.
On the other hand, giving the barrel a clean once in a while in order to leave a protective layer to ward off corrosion is a sensible argument for de-leading your rifling.
Precharged pneumatic airguns don’t fire oil particulates down the barrel unlike springers, so with the moisture content present in compressed air, internal condensation forming on the bare metal of the bore could play host to the formation of rust.
Let’s say you fall into the ‘do’ camp. There are different approaches to cleaning an airgun’s barrel.
Some suggest using conventional brushes on a rod, but I really don’t see the need. Any build-up is going to be fairly soft – we’re not talking baked-on powder fouling. Plus, metal bore rods can easily cause damage, both on entry and mid-bore.
The most common cleaning system is a fabric patch on a ‘pull-through’ – a plastic-coated steel trace; I use a loop of Kevlar string, with a patch of Napier’s Rifle Clean cloth. This cloth can be bought it in pre-cut lengths or on a roll which lasts ages, given you’re only tearing off 7.5cm or so for each patch.
While it’s sensible to apply a lubricant to the patch, I’d avoid using firearms barrel solvents. Besides not being necessary in the airgun’s case, whatever goes down the barrel might find its way back into the transfer port – where it could cause heavy dieseling in the case of a springer, or degradation of the all-important seals of a PCP.
I favour a light oil of the type used for military weapons – applied sparingly on each patch. Any quality light oil will do, but it should be silicone-free.
While getting a pull-through down the bore of a break-barrel is easy, it’s a little trickier in the case of a fixed-barrel springer, or a bolt-action PCP. In any event, when using a pull-through, you must remove any silencer (after first ensuring the gun is completely safe, of course).
If you can’t take the silencer off, use a drinking straw ‘liner’ to make sure the pull-through doesn’t get snagged on any baffles.
If there’s one thing most concur with on the subject, it’s the direction in which the barrel should be cleaned – from breech to muzzle, the direction of the pellet. So feed your pull-through down from the muzzle before ‘loading’ it with a patch and pulling it back through.
Same if you’re using a cleaning rod in a fixed-barrel gun: don’t attach the patch to the jag until it’s appeared at the breech – although you can rod through from the breech if you have easy access to it, as on a break-barrel.
But always pull back slowly, keeping the rod or cord straight; you don’t want to pull to one side of the muzzle crown as you could damage it.
Although I favour the ‘do not’ line of thinking, for the purposes of this article, I broke my own golden rule to show you what might happen if you clean a barrel that’s giving perfectly acceptable results.
Groups out of my ‘guinea pig’ PCP at 35 yards with .22 Rangemaster Sovereign were tight – and the chrono showed an average muzzle velocity of 568 fps.
I then cleaned the rifle’s barrel; it took five pull-throughs before the patch was clean. I made my final patch a dry one, although if I were considering storing the rifle, I’d have given it a drop of protective lubricant.
Analysing each of the patches, the first showed lead, with possibly some oil mixed in along with fragments of pellet swarf, dust and debris. The debris wasn’t bad, but the dark fouling was very evident. The patches then got progressively cleaner.
With a super-clean bore, I then fired a few shots over the chrono – they averaged a slightly higher speed, albeit by only 5fps. Interestingly, my first groups on paper targets with the newly-cleaned barrel were ‘off zero’ (by a few clicks at 35 yards), and a little loose.
Progressively, however, the groups moved back to the original zero point, and tightened to their former glory. In total, I suppose it took around 60 shots to ‘restore’ things.
While my article has given no definitive answer as to whether you should or shouldn’t clean your airgun’s barrel, I hope it’s shown you that if you do choose to scrub up, you’ll know that your rifle won’t get back to full accuracy potential until the barrel has once again leaded-in.
That, alone, is a good enough reason for only cleaning a barrel when it’s absolutely necessary… but I’m guessing many of you may completely disagree with me!