Weihrauch HW100TSE

Air Rifle Maintenance, Part 2

This maintenance article is directed at those who wish to service their own Weihrauch air rifle and may lack the skills or confidence to do so without guidance.

Stripping your Weihrauch Air Rifle

The first step is to ensure that the air rifle is UNLOADED. That helps…..

If you don’t have a rifle stand or mount, then the next best thing is a flat table at a comfortable height to work on with good lighting, just like the kitchen or dining table. If you use one of these tables, the best way to strip the rifle is on a blanket over the bench and an old sheet (now its ‘old’….) covering the blanket.

This provides a soft rest for your air rifle and it protects your kitchen or dining table that you may be using while your wife is out shopping. Trust me here, you need a blanket under a sheet to protect the table and the sheet minimises fibres from sticking to oiled parts while doing periodic air rifle maintenance.

With the Weihrauch HW25, 30, 50, 80, 95 etc, all being ‘break barrel’ air rifles, you clean these in a slightly different sequence than you do the HW77/97 loading arm models or the HW100 PCPs.

With all air rifle models, first ‘crack’ the screws prior to un-screwing them completely. By ‘cracking’, I mean just un-tension each screw in turn prior to removing them so that no one screw is left under full tension to the stock.

Then unscrew the 2 side stocck screws in the stock and the 2 screws through the trigger guard on all but the HW100 models. The mechanism can then be lifted off. Be careful to retain the flat and star washers from the stock sides.

With the HW100T,S,TK and SK, being PCP air rifles, the mechanism is held in place by 2 screws with Allen key heads set in cupped retainers into the underside of the stock.

Break Barrel Air Rifle Models

With the break barrel models of air guns, once the stock is removed I would start by wiping the gun down with a lightly oiled cloth first if the rifle is in a clean condition. If it is grubby, then some degreaser sprayed onto a cloth and used to wipe the gun down is the first step.

Then crack open the barrel and put some clean cloth over the detent and in front of the air chamber to keep any loose debris from entering. Next insert a pull through rod from the end of the barrel towards the air chamber. Screw on a pull through jag, attach a patch and damp it with some Bore Cleaner and pull it through, noting of course how dirty it is. Repeat this a couple of times using a new patch each time.

Substitute the cloth patch loop for a bronze brush using some Bore Cleaner solution if the bore has excessive or hard to move build up, then pull this through the barrel. Then wash the bronze brush clean noting any contaminants. If it comes through dirty then clean the brush and repeat the action a couple of times.

Do NOT pull through a cloth patch or bronze brush twice without replacing the patch or cleaning the brush.

Finally, pull through a couple of dry patches noting that they should now be clean and dry. If this is not the case, inspect the bore with a torch and repeat the cleaning using a bronze brush on the pull through followed by cloth patches once more.

You will find that if you clean your barrel regularly that a patch and cleaning fluid is all you need. However, if you use cheap pellets or you are not one that cleans his gun that regularly, then you may need to initiate cleaning your barrel with a bronze brush first before using the patches.

Air rifle maintenance is not restricted to just cleaning and oiling your airgun, storage is important too. When you are storing the air rifle, lightly oil a patch and pull it through the barrel to prevent rust while it is stored for any given length of time. Do NOT over-oil the patch, just a light oiling is all that is needed.

The air rifle mechanism should then be checked for broken springs, loose screws, binding or wear marks that indicated misalignment etc. Lightly oil the pins and detent, trigger pins and loading arm pins using a light machine oil (3 in 1 Oil, light Machine Oil or a genuine Gun Oil). Then wipe down the rifle with a lightly oiled cloth one final time prior to reassembling it into the stock.

Locate and start each screw a few turns until all screws are in place, then hand manoeuvre the rifle mechanism to ensure that it is nested correctly in the stock inletting. Next, lightly nip the screws up in turn, finally securing them with a firm nip rather than screwing the crap out of them. The screws need to be snug and not over-tightened.

NOTE: If you are storing the air rifle, break the barrel and put some clean cloth over the barrel detent and in-front of the air chamber to catch any oil that may drip down. Store it this way if possible. If you have to close the barrel due to storage restraints, then I suggest that you put a Cleaning Pellet in the bore prior to closing it. This will stop any oil from draining through into the air chamber which can cause dieseling and subsequent damage.

Cleaning Pellet by VFG

VFG Cleaning Pellets for most calibres of air rifle

Under-lever Loading Arm Models such as the HW77 and HW97K

The cleaning of the bore on HW77, HW77K and HW97K is done using the same steps as above with the following differences:

Access to the barrel at the pellet end is restricted due to the chamber guide covering the pellet entry end of the barrel. So what I do is clean the action after removing it from the stock while checking the Bear Trap spring is in place and not unserviceable – this is a VERY IMPORTANT part of air rifle maintenance. This image below is a Bear Trap that stops the trigger from being inadvertently pulled when the loading arm is down. The springs lose their tension over a long period and in cases where the air rifle has been neglected, I have found the spring missing on more than one occasion.

Bear Trap And Spring.

Bear Trap And Spring.

Air Rifle Maintenance Diagram

HW77K ready to assemble with the Bear Trap indicated (Note Trigger group is in the “fired” position.)

Once the mechanism is cleaned down, I then check the trigger assembly for dirt or dust and if it looks fouled at all, it is removed and it gets cleaned in a bath. Then the trigger mechanism is oiled and sears are greased prior to reassembly. The moving parts and pins are lubricated next and the air rifle is reassembled. If you are a guy who is not really “into” air rifle maintenance, then just stick to cleaning and oiling the air rifle. If the trigger group looks like it needs removing and cleaning, get a gunsmith or a local gun club enthusiast to do it for you as it is not an area where you should experiment.

So at this stage, we have removed the air rifle mechanism from the stock, cleaned it, checked out the trigger mechanism, oiled it, checked the Bear Trap and refitted the action to the stock ready for the barrel cleaning.

For those of you new to the term Bear Trap, it refers to the sliding gate that is held open when the loading arm is locked up in place. Once the loading arm is drawn down, the small spring you see in the image above, has it’s tension relieved and in so doing this, pulls the sliding gate to move under the trigger fulcrum, effectively preventing the trigger from being operated.

Safety first when doing air rifle maintenance.

I then cock the air rifle and secure the loading arm tight in the fully down position. I do this using a nylon strap to hold the loading arm in the drawn down position to eliminate any possible chance that it may let go and fly back up under pressure, taking off any digits in the loading gate. Ouch….. Unlikely but not impossible, especially when working on a client’s gun as you don’t know what they may have done with it.

air rifle maintenance safety point

HW77 With Loading Arm Locked Down.

Then I clean the barrel out as per the Break Barrel sequence. Once finished, I put a cleaning pellet in place and after releasing the loading arm, I fire that into the ground. This allows you to unload the gun and it also removes any surplus lubricant in the bore. When firing a cleaning pellet, it is best to push the cleaning pellet into the bore ahead of a regular pellet, so when you fire it, the regular pellet creates the back pressure needed to prevent spring and seal damage when fired.

If your air rifle barrel is cleaned regularly, then all you need to do is use patches drawn through the bore with cleaning fluid and you may get away with just pulling down the loading arm sufficiently to allow you to hook the patch onto the jag and then pull it through. Some guys tell me they do it this way but as I am working with Weihrauchs everyday, I find that this method is a bit slow and cumbersome though it may work for you, so try it. Air rifle maintenance is not limited to how I do things, there are other methods worth exploring.

If you need to store your air rifle for a while, then oil the bore as per Break Barrel models. To do this, you pull down the loading arm sufficiently to allow you to insert an oiled patch and pull it back through. You can then fit an air rifle cleaning pellet before relocating the loading arm into the barrel detent socket. This will put a cleaning pellet in the bore while the rifle is NOT loaded. If you pull the loading arm down too far it will cock and you will need to fire it prior to repeating this process.

It is important that you do not get any oil, be it Silicon oil, Mobil 1 synthetic oil or traditional “Grandpa’s” Gun oil into the air chamber as this can cause dieseling: this is a form of combustion that takes place when solvents and or oil are placed under great pressure such as firing the air rifle.

Repeated dieseling can cause massive damage and early retirement of the seal which can then allow metal on metal contact at the end of the spring travel, sometimes rendering the rifle unserviceable. I have seen this on several occasions, it’s not a way to go.

When you are performing any sort of air rifle maintenance on any sort of springer, be it under-lever or break barrel, have a good look at the visible area of the spring. This needs to stay clean and to do this a gun bag or case while travelling is a must as you can’t afford to contaminate the oiled spring with red dust or the like as this would necessitate pulling down the air rifle completely, cleaning it totally and rebuilding it.

Remember too, that when storing your air rifle in a gun bag, do not leave it there for more than a few days or you may find rust forming inside due to the insulation effect of the bag causing condensation.

If like me you live near the sea, then you need be extra vigilant to ensure that dry air borne salt spray does not enter your work space area where you keep or work on your rifle. This dry salt air absorbs moisture as the humidity cycles through day and night and anything not well painted or lubricated will be adversely affected or at risk. Please note this if you live near the sea as performing regular air rifle maintenance will be very necessary to avoid rust.

Weihrauch HW100 PCP

This Weihrauch HW100 PCP air rifle is cleaned much the same way as the others except I prefer to clean the bore while the gun is cradled in the rifle stand.

Again, cleaning the bore should be just that, cleaning it and not moving crap from the bore into or onto other parts of the air rifle. So, care must be taken to draw the pull-though from the pellet entry end out through the end of the barrel. With PCP air rifles you cannot allow dirt or oil to contaminate any parts of the complex air chamber port.

Other points to note are that when cleaning down around the pressure chamber, be very careful not to allow any oil or solvent what so ever to enter the cylinder delivery port, or threads etc. High pressures of 200 Bar and oil do not mix and are extremely combustible!

Extra care should be taken with PCP  air rifles when doing routine maintenance and if you lack the skill set or are reluctant to do it for any reason at all, I suggest that you engage a gunsmith with air gun experience to do it for you. Cost is peanuts and the exposure to risk of damage or incorrect maintenance is not yours. However, in saying this, you need to find a gunsmith who actually does work on airguns as many have little if no experience with air rifles, with their knowledge base being around the more popular rim and centre fire guns.

How often should air rifle maintenance be carried out?

I get asked this a lot. Just like everything else on this site, this is how I do things and I accept that there are other ways to do things as well, I respect that. Each to his own as they say. In saying that however, what I put here works for me and has done for over 50 years without too many mishaps and still counting….

If you are an avid Target shooter then I expect that after each session you would at least clean the air rifle bore if not the whole rifle. This is what it takes to stay on top of the game as well you would know.

Now for you guys that are into hunting and vermin control let me say this: Cleaning your air rifle is probably as quick as reading this article, maybe quicker once you have mastered a technique. So, if you are punching out quite a few pellets each week, I would expect that the air rifle be cleaned at least once a week if not once a month, and not just when it screws up.

For those of you shooting in damp and humid conditions I would be dropping the stock each time I take it out as moisture between the stock and mechanism will not help the finish. Go shooting in dry and dusty conditions and I would pull it down just as regularly, not to stop the rust but to keep sand and dust out of the mechanism.

In saying this, I would also expect that once you have pulled down your air rifle a few times you will know just how dirty it is after each shoot, so you will then be better qualified to know how frequently to pull it down for a clean.

There are still a number of air rifle enthusiasts who prefer not to do air rifle maintenance work on their own rifles, so if this is you, stick to just oiling it and get a gunsmith with air rifle experience to service it in more detail. For those of you who send me their rifles for tuning, service work or repairs, please only send the mechanism, that is, leave the gun stock at home. I have plenty of Weihrauch Air Rifle stocks here to mount your rifle mechanism and anyway, it will cost you less in the Post that way.

Another tip for sending your rifle by Post is to send it Registered mail and package it carefully without making it look like a firearm. Furthermore, NSW restricts sending firearms by Post so you would need to send it by a freighting company if you live there. When addressing any package to a Gun Dealer, whether it is to me or another Dealer, try not to mention the word ‘Gun’ in the address and just use the Dealer’s name instead, this way you at least disguise the fact that the package is firearm related to some degree.

The bottom line guys is this; the cleaner your air rifle the better it will shoot, the longer it will last, the safer it will be, the better it will serve you and the longer it will retain its value, period. Air rifle maintenance is the key to getting longevity from your airgun.


Ian McIntosh

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