Pneumatic Pnews

Monday, November 20, 2006

Let's talk about oiling a spring gun

by Tex Force

Spring gun oiling is a subject that baffles many owners. They buy a rifle, then they hear about oiling and wonder what they should do. I'll try to simplify the subject of spring gun oiling.

Where to oil?
There are two main places where a spring gun may need oil and a host of smaller ones. The smaller ones are various parts of the cocking linkage that need oil to operate smoothly. Every gun is different, but the basic guideline is this: if it moves, it needs to be lubricated. On breakbarrels, the barrel joint is obvious. On underlevers, the cocking linkage has several spots to lube. It's easy to figure out when the gun is in front of you.

Don't over-oil!
It's better to use too little oil than too much. A spring gun comes from the factory lubricated and ready to go for the most part. Lube it only when you can see a reason to...joints start squeaking, etc. You shouldn't need to lube any more than once a year, and I have guns I haven't lubed in five years.

The mainspring
The mainspring is one of two principal spots to lube. Use lube very sparingly. Just because a spring looks dry doesn't mean that it is. Diana mainsprings almost always look dry when they actually have adequate lubrication for several years. They are shot-peened, which creates a rough surface that appears dry but actually holds lubricant in the tiny pits on the surface of the spring.

Put lubricating oil on the mainspring. A good product is RWS Spring Cylinder oil. That sounds strange, but you need to know that chamber oil IS NOT suitable for lubricating metal-to-metal surfaces. It's too thin and will not protect the metal parts, which then rub together and create shiny spots known as galling. Always use a lubricating oil on the mainspring. If the spring is so dry that it has shiny spots, use about 10 drops of oil applied through the cocking slot. The action of cocking and firing distributes the oils, so don't worry about not being able to see the entire spring. If just the spring needs some oil, use five drops.

The chamber
You lubricate the chamber for an entirely different reason. The oil creates an airtight seal around the rim of the piston seal, making the gun more efficient. There's a danger in oiling the chamber. Excess oil burns off in loud explosions called detonations. This is not dieseling, which every spring gun does. Detonations are much worse and can break parts in a gun - especially the mainspring. If you lube the chamber of a gun that has a modern synthetic piston seal, use no more than two drops of oil down the air transfer port (that hole behind the barrel).

How do you know if you have a synthetic piston seal?
The age of the gun is the determinant. Almost all airguns made since 1980 have synthetic piston seals. Older guns had leather seals, and those got a lot more lubrication - maybe five drops every six months.

Some guns want very little oil
RWS Diana airguns such as the model 34 need next to no lubrication. Maybe one drop of RWS Chamber Lube every year or 3,000 pellets. HW guns need more - maybe two drops every 2,000 shots or year. Chinese guns also need more. The TF99 and 97 should be lubed like an HW gun. The rule to follow if you don't know differently is to err on the side of less rather than more lubrication.

Lubricating a spring-piston airgun is not a daunting task, nor it is one you must do often. If you watch how your gun performs, it will often tell you when it needs oil.


  • Hi T.F.,

    Thanks for the timely article. I disassembled my Diana 52 this weekend, to fix a user malfunction I recently created with the scope mounting rail. Long story I won't go into.

    Also, I haven't fired this air rifle in many years (another long story) and was concerned about lubrication. As you described, I saw some of the mainspring through various holes/slots in the tube. Looked pretty dry to me. Now I understand why!

    After I messed up the mounting rail I wouldn't shoot my Diana for fear of metal cuttings inside the action getting into the trigger unit. Got that issue fixed now.

    So, I'm going to wipe-clean and lube it like you've described (sparingly - with applicable Diana/RWS oils I've got), reassemble, and see how she shoots.

    I bought the various Jim Maccari lube products, but reading your article inspired me to get a feel for how the rifle shoots before and after... wipe-clean and re-oil versus complete degreasing and "tar" application.

    It's been so long I don't remember what my 48/52 sounds like when fired. I think a lube comparison will be interesting. Comparing pellet velocity with a chrony, too.


    By Anonymous GadgetHead, at 12:01 PM, November 20, 2006  

  • Is it important which kind of oil I use?


    By Anonymous Anonymous, at 12:11 AM, November 22, 2006  

  • GadgetHead,

    It looks like you caught your mistake in time. Good for you!

    The Maccari lube will last far longer than the oil-based lubes I discussed here, but they do require disassembly, so I didn't mention them.

    Thanks for your comments,


    By Anonymous Tex Force, at 6:47 AM, November 22, 2006  

  • Alex,

    Yes it is! Pure silicone oil with a high flashpoint for the compression chamber and lubricating oil for everything else.


    By Anonymous Tex Force, at 6:48 AM, November 22, 2006  

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