The following article was originally published on the Airgun Academy Blog by Tom Gaylord and covers all of the basics of airgun maintenance. You can view the original article here.
by Tom Gaylord
Writing as B.B. Pelletier
This report covers:
I received this question on Tuesday.
“I just received an LG cal 4.5 mod 55 Walther’s patent air rifle. It’s a great gift, and I would like to keep it in good condition. I live in Europe though, And like most Europeans, I know almost nothing about guns.
Could you write an article about basic airgun maintenance and important things to check when laying hands on an old gun?
Thanks in advance for any help, Jean”
Good for everyone
With the enormous number of readers we have, I imagine Jean is not alone with his question. I put the answer here in the History section because his Walther LG 55 is a vintage breakbarrel spring-piston airgun that’s no longer made. It was made from 1955 to 1967, according to the Blue Book of Airguns. For some of those years (until 1963) it was Walther’s top target air rifle, and even today it has a smoothness and robust construction that cannot be overlooked. You don’t have to know airguns to recognize the quality of this rifle.
The LG (stands for Luft Gewehr, which is German for air rifle) 55 rifle was followed by Walther’s LGV — the top of their spring-piston target rifle line. It was manufactured from 1963 and remained in the line until 1972. By that time, technology was replacing spring-piston air rifles for target use, and Walther’s LGR, a single stroke pneumatic that would come out in 1974, was far and away a more refined target rifle.
Back to the LG55
The reason I put this report in the historical section is because these older spring-piston airguns often have leather piston seals. Leather seals need lots of oil on the piston seal. It keeps the leather supple enough to do its job.
A spring-piston airgun works by means of a piston being shoved forward by a spring when the gun fires. The piston compresses the air in front of it and pushes it through an air transfer port at the end of the compression chamber. The amount of air compressed is very small, but the pressures generated are quite high. Like the cork from a champaign bottle, the pellet is overcome by this intense burst of pressure and, when it can no longer resist, it goes speeding down the barrel.
Spring-piston airguns have no valves. The piston compresses the air that travels through the transfer port to the back of the pellet. It’s simple and reliable.
The air transfer port at the front end of the compression chamber conducts the air compressed by the piston to the rear of the pellet that’s sitting in the barrel.
Here is a closer look at the transfer port.
Oiling the piston seal
The reason I’m telling you this is because you need to oil the piston seal from time to time. If the seal is leather, oiling with 5 drops once a month is not too much or too often. If it’s synthetic, you can oil it once every 6 months with regular use or once every 1,000 shots.
The seal in the Walther LG 55 is synthetic, and the original ones have a problem. The material the original piston seals are made of dry rots over time. They all do, and will eventually fai, regardless of whether the gun is fired. Jean, this is the first thing you need to watch for. If the pellet starts moving very slowly, to the point of not coming out of the barrel, the seal is bad. Sometimes you will see chunks of a yellow or brown waxy material in the barrel. Those are particles of the dry-rotted seal that have broken off. When you see them you know for certain the rest of the seal is gone, too.
Diana target rifles (models 60, 61, 65, 66 and 75) also have this problem. So do the original Walther LGVs — not the ones made today, but the ones made in the 1960s and ’70s. The FWB models 121, 124 and 127 also have this problem.
Replacement seals for all these airguns are available today and they are made from material that does not break down. They can be thought of as lifetime seals — especially at the lower power levels of these rifles.
How to tell
Disassembly is the most positive way to know if your gun has an original seal that’s gone bad or a new seal, but most new airgunners don’t want to do that. The good news is, it’s pretty easy to find out without disassembly — by examining the rifle closely and by shooting it. Look in the barrel for chunks of a yellow or brown material. If you see them, don’t shoot the gun any longer until the seal is replaced. If you notice the pellet start coming out slower (it will be very slow) the seal needs replacing. Stop shooting until it is replaced. If the gun vibrates hard or has a sharp jolt when shot — especially if it jumps forward a lot, the seal needs replacing. All spring piston rifles jump forward when they fire — this would be an exaggerated movement. If you are so new that you can’t tell if the forward recoil is excessive, better stop and have someone who knows airguns examine the rifle.
How to oil the piston seal
The pistol seals on these older spring rifles need to be oiled much more than modern ones. One drop of silicone chamber oil every 6 months or every 1,000 shots is about right for vintage guns with synthetic seals like the LG 55. Do not use household oil or regular silicone oil from a hardware store for this. The oil must be silicone chamber oil because of the high heat the gun generates when it fires.
To oil, cock the rifle but don’t close the barrel. Look at the flat end of the spring tube that is now exposed and you will see a small hole that aligns with the rear of the barrel when it’s closed. That is the air transfer port.
This is what you are looking for. An air transfer port.
Drop one drop of silicone chamber oil into this hole, then uncock the rifle by holding the barrel at the muzzle, pulling the trigger and slowly letting the piston go forward. Let the gun stand on its butt for a couple hours before shooting.
Another way to do this is to stand the rifle on its butt and drop two drops of oil down the barrel. The extra drop will stay on the inside of the barrel. Let the gun stand for 12 hours before shooting.
Oiling the piston seal is the biggest maintenance step with this rifle. You can also oil all the hinge points of the cocking linkage with household oil or good gun oil. And it doesn’t hurt to oil the mainspring with the same gun oil. To do that the rifle comes out of the stock. Remove the two forearm screws and the front triggerguard screw to remove the stock. Then you will be able to see a portion of the mainspring through the cocking slot in the rear of the spring tube. Drop 5-10 drops of oil through this slot then cock and uncock the rifle several times to spread it around.
Cleaning the barrel
I have one piece of advice on cleaning the barrel. Don’t do it! It doesn’t need it. If you shoot good lead pellets all the time your barrel should never get dirty. There is no residue from gunpowder and lead pellets that move at less than 800 feet per second don’t leave deposits in a well-rifled bore. Your Walther’s barrel is rifled very well and the gun shoots a lot less than 800 f.p.s.
Your LG 55 is a target rifle. It was made to shoot target pellets. Those are flat-nosed pellets called wadcutters. You can shoot other shapes if you want, but wadcutters are what your rifle was designed for.
Shoot lead pellets, only. Your rifle was not designed for lead-free pellets. They might work very well, but I haven’t tested a vintage Walther with lead-free pellets, so I don’t know how it will perform.
Cleaning the outside
Ballistol! This is the oil that’s used all over the world by armies for their automatic weapons. This is the oil that coated my friend Mac’s gun collection that stood in water for a week and never rusted! This is the oil that dissolves rust. Saturate a soft rag with Ballistol and keep it in a plastic bag to wipe down your air rifle after handling.
Jean, that’s all that comes to my mind at the moment. Tell us how your rifle shoots. Is it smooth? Does it cock easily? Is it accurate?