by Tom Gaylord, a.k.a. B.B. Pelletier
This blog is for those who are new to shooting and to airguns. Sometimes, we have to address the basics, and that’s what I’m going to do today. I’m inviting the veteran shooters to chime in with their own ideas of what the new airgunner should avoid.
For reasons I cannot fathom, new shooters think they need to clean their airguns even more than firearms are cleaned. I know people who never clean their .22 rimfires until they start to malfunction, yet these same people don’t hesitate to take a bore brush to the barrel of their favorite air rifle every chance they get. It isn’t necessary to clean an airgun barrel that often, and it actually exposes it to possible damage from the cleaning process gone wrong.
Why do we clean a gun?
Historically, guns used what we now call black powder, whose residue both attracts moisture and then turns it into sulphuric acid. It begins to do this in less than 24 hours following shooting, so cleaning was/is essential if the bore was to be preserved. Later, when smokeless powders were developed, the early primers that ignited them contained compounds that were just as corrosive to the bore as black powder residue. A great many .22 rimfire rifles have lost all their rifling from the combined activities of this primer-based corrosion, coupled with over-zealous cleaning.
More recently, shooters have discovered that the jacketed bullets of centerfire cartridges will quickly foul barrels with metal deposits. While this doesn’t corrode the metal, it does fill the rifling grooves with jacket metal until all hope of accuracy is lost. So, the metal fouling has to be removed with a combination of chemical and mechanical action.
The modern .22 rimfire, in sharp contrast, uses clean-burning powder, clean priming and shoots clean lead bullets at low velocities. Nothing in its makeup or operation requires frequent cleaning. Those who shoot .22s can get away with not cleaning their guns for many hundreds and even thousands of rounds. Eventually, there will be a buildup of powder fouling even in these clean guns, but the contrast with centerfire guns is vivid.
Finally, there are the airguns. They neither burn powder nor use primers, so there’s no residue. They shoot at low velocities (compared to many firearms) and use clean lead pellets, so there’s little metal fouling. Only with some of the more powerful airguns do the velocities get fast enough to scrape off some lead from the pellets. And some barrels seem more prone to scrape off lead than others. That, alone, is the sole cause for buildup in an airgun.
In contrast to a firearm, an airgun can be fired tens of thousands of times between cleanings…and some lower-velocity airguns may never need cleaning at all. Those with brass or bronze barrels are entirely impervious to cleaning requirements.
The time to clean your airgun is when the accuracy falls off, not before. Do not clean an airgun barrel on a regular schedule — they simply don’t need it.
2. Disassembly without a plan
I’ve done this and so have many of you. The gun isn’t working right, so we take it apart to find out why. Then, we haven’t got a clue how to get it back together. That results in a basket case of parts that somebody else will be able to buy for a song. Don’t create bargains for others! Before you take an airgun apart, give some thought to what it takes to put it together again.
The way to do this is to first research the gun on the internet, to see if there are any disassembly or assembly problems. If there are known issues with a gun, there should be plenty of information on the internet.
Another thing to look for is if any special tools or equipment are needed. With spring guns, you usually need a mainspring compressor to safely disassemble and assemble the gun. And if you’re disassembling a BB gun like a Daisy Red Ryder, you need to make a special fixture to hold the gun while the mainspring is compressed and parts are removed. Unless you have three arms, this fixture is absolutely necessary.
Then, there are guns that are assembled during manufacture in ways that make them almost impossible to repair. One good example of this is the barrel of a Benjamin 392, which is soldered onto the pump tube at the factory. If the solder joint is ever broken, it’s next to impossible to repair. That’s because the joint is very long and is difficult to keep an even heat on the entire joint at the same time. The solder flows in some places, but clots in others. When you move the heat to the places where it’s clotted, you lose the solder that flowed before.
Don’t attempt repairs or modifications unless you know you can do the entire job. Better to spend some money to get the job done right by an airgunsmith than to charge in and break or lose some irreplaceable part.
Some of the new owners’ manuals tell people to oil the compression chamber on a frequent schedule. While oiling was appropriate for guns with leather piston seals, the newer synthetic seals don’t need nearly as much. Over-oiling causes detonations that can damage the gun if they’re allowed to continue; and once they start, there’s almost no way to get them to stop. All spring guns diesel; but when they go off with a loud “bang,” that puts a strain on the mechanism.
I always like to err on the side of under-oiling because all that does is make noise during cocking. Over-oiling causes problems, though, and in extreme cases the airgun must be disassembled and dried out.
There are places to oil besides the compression chamber. Linkages need a drop every now and then, and the wood parts can always benefit from a CO2 cartridge before it is pierced. The best oil for this job is Crosman Pellgunoil, and a CO2 shooter needs to always have some on hand. The oil is blown through the gun’s valve when the cartridge is pierced; and it gets on all the sealing surfaces, making a tight seal against gas loss. It’s the No. 1 maintenance action a CO2 gunner can take, and you absolutely cannot overdo it.
So, what happens when an airgun is not oiled enough? It makes noises to tell you. Spring-piston guns will honk like a goose when they’re cocked if there isn’t enough oil on the piston seal. Mainsprings will crack and crinch when cocked as they slip their coils when they don’t have enough oil. And the fork that the breech sits in will become shiny if there isn’t enough grease between it and the breech. Also, the cocking effort will increase dramatically.
CO2 and pneumatic guns will develop slow leaks when they need oil. Their seals cannot do the job without a thin film of oil on all their surfaces. But if the gun is holding air, stop with the oil — except in the case of CO2 guns, as noted before.
This fault is as old as the hills and is a classic mistake a newcomer will make. If 10 pump strokes give X amount of power, shouldn’t 15 pump strokes give 1.5X? No! In fact, they do just the opposite. Over-pump a pneumatic or overfill it from a scuba tank, and the velocity takes a nosedive. It will drop all the way to zero, at which point the valve is locked shut by the excessive pressure in the gun. Imagine a door being held shut by several strong people. No amount of pushing will open it. You have to wait for some of the people to leave or, in the case of the gun, for some of the internal pressure to drop. That can take weeks and even months!
A pneumatic gun is designed to work within a certain pressure margin. Too little pressure and the power drops. Too much pressure and the power drops. Remember it this way — putting more gas into a car’s tank will not make it go any faster.
With CO2, you don’t have to add pressure; and in fact, there’s no straightforward way to do it. If you were to increase the gas pressure somehow, all that would happen is more gas would condense to liquid. The pressure would remain the same. But if the outside temperature should go up, the gas pressure will increase as well because the gas pressure is dependent on temperature. Operate your CO2 guns when the temperature is between about 60 degrees and 90 degrees F. And don’t leave a CO2 gun lying in the direct sun, even on a relatively cool day, because the gun will absorb the sun’s heat and will go into valve lock.
There you go — 5 simple things to remember about airguns and their operation. Perhaps our readers can suggest more?