A guide to airgun servicing

Andy McLachlan explains what’s required to get your target rifle in tip tip shooting condition – and to make sure it stays that way

Andy’s removed the hammer assembly from the action block of his Walther so it can be properly cleaned and inspected

In my last article I wrote about the many considerations that the target shooter must take on board following the fall of some dropping shots. These are the individual shots that fall well outside of the point of aim and usually end up destroying the good work you have put into the production of a match-winning target card.

We have already considered just how important it is to make sure that our pellets are properly prepared and that our scope allows us to make the most of our combination’s accuracy on the range. 

If we are confident that all the ancillary equipment we are using is fully serviceable and that we are ourselves capable of maintaining proper trigger control, we are now left with the gun itself being of concern if it cannot produce the standards of accuracy which it did when new.

This may also be the case if we have purchased a second-hand gun that doesn’t perform as well as we think it should. Very often, it is simply a case of finding the correct ammunition for the individual barrel, at which point the gun magically shoots its head off once again. 

It is always worthwhile asking a previous owner which type, or preferably batch, of pellets they found suited that particular gun as you can obviously save yourself a lot of time, effort and expense in doing so.

Once we have considered the ammunition, we then need to look at the barrel and make sure that it has been cleaned properly. 

Unlike shotguns, it is not immediately obvious that an airgun barrel is dirty as we will not see pellet residue blocking up the lands of the rifling and clogging up the choke as the pellet is constricted on its way out of the barrel. A quick check reveals absolutely nothing for us. 

All the hammer and spring needed were a good clean – it’s amazing what a difference something as simple as this can make

We must rely upon a system of regular barrel cleaning designed to reduce the build-up of unwanted lead residue and the sudden drop in accuracy that appears when a barrel goes “off”, as can happen for those not wishing to pursue regular maintenance.

There has been much written by myself and others regarding the methodology of barrel cleaning, but to summarise my own cleaning regime, I will use a couple of Birchwood Casey blue barrel cleaning patches that have been dampened with some LT 1 pellet preparation fluid. 

It’s important not to soak the patches otherwise the excess fluid will end up in the regulator/firing mechanism. I usually carry out my cleaning regime with the gun upside down, again so as not to allow any excess fluid to enter the mechanism. 

The dampened patches will be followed by however many dry patches it takes for the barrel to register no remaining residue. This is easy to see as they’ll appear nice and clean following their pull through the barrel. 

Pulling patches too vigorously through some barrels may result in the O-ring seal being popped out of its seat, requiring replacement, so if your gun is of this design, go carefully with the pull-through.

As I shoot my target rifles frequently, I make sure that this process occurs every 500 rounds without fail, and yes, I can notice the difference in pinpoint accuracy if I fail to maintain this system. 

If I were to just carry on shooting until the barrel went off, this would result in a gradual, but sometimes dramatic decrease in accuracy – which is the reverse of what you want when considering why the last couple of pellets on a particularly impressive card have fallen short of the bull. I have also seen a barrel suddenly go off on the firing line of an HFT competition.

If you have discovered that your barrel is not performing as well as it once did and accuracy fails to return, you may need to consider the nuclear option of barrel paste, felts and cleaning rods to really polish the barrel’s internals, although this should only be resorted to when a dramatic decrease in accuracy becomes apparent. 

The action block has now been reassembled following its strip-down and service, and will be good for thousands more shots

It often takes thoroughly cleaned and polished barrel internals a couple of hundred shots to fully bed in afterwards, so take this into account as well.

Presuming that you have continued to maintain a barrel cleaning regime and are now starting to notice the odd flyer appearing upon the target, we might have discovered other issues within the gun’s mechanism that result in wayward shots. 

If you are using a spring-powered rifle, particularly a new one that is still running in, simply retightening the stock attachment screws carefully and with a correctly fitting bit will alleviate the issue. 

This is something I have witnessed many times, particularly with beginners who are not aware of how mechanically powered guns lose accuracy due to their actions not being tight within the stock.

However, most airgun target shooters will be using a PCP, and the management of the high-pressure air within the gun’s action often does result in a reduction in accuracy and ability to retain a charge in the cylinder. 

Shooters like Walter Bond always make sure that their target rifles are serviced regularly so they can perform at their very best

This means a pressure seal has failed and will require replacement before the gun will operate effectively. As with all things mechanical (or pneumatic), if you are unsure how to go about tackling your own airgun repairs, take it to an expert who will make sure all is well and that the gun is safe when returned.

As a teacher of motor vehicle technicians for decades, I always make sure that my students have been made fully aware of just how important it is to maintain strict regimes of regular and itemised maintenance for the duration of a vehicle’s service life. And of course, those same principles will also apply to proper gun maintenance.  

If I consider how frequently I have shot my beloved Walther LG400 over the past two years, it would have to be said that certain items within the action that should have been serviced, such as the pressure regulator and hammer spring, have not been properly checked. 

If I count the average number of shots fired by this gun at approximately 400 every week for two years, this equates to a total of 38,400 shots. 

Taking into account weeks of shooting other guns, this high shot count may well drop a bit, but even so you can see that the gun has already lived a busy life. The fact that it has not sprung a pressure leak and continues to deliver speaks volumes for the quality of its design and manufacture.

What I recently decided to do is to remove the gun’s hammer spring and hammer for a clean followed by an inspection, and I have also ordered a regulator and some spare seals from the ever-helpful Judith at schiessport-billhartz.eu

If you do need to fit any new parts, try to use Original Equipment Manufacturer components to ensure quality and compatibility

Following my removal of the hammer and spring from within the action of the Walther, I took the opportunity of fully cleaning out the hammer cavity to remove all the old grease.

As with my Steyr target rifles, I have always preferred to let the hammer run dry in the action as this will lead to more consistency due to any lubricant not influencing the shot-to-shot velocity of the mechanism. Incidentally, the place to go for guidance regarding target rifle maintenance is Sven at Airgun Accuracy. 

For those of you interested in all things target rifle, this really is a superb site and provides a good understanding and practical guidance for those who feel competent enough to attempt some maintenance tasks.

Regular maintenance is vitally important if we wish to maintain the amazing levels of accuracy available from today’s pre-charged pneumatic target rifles. If you are not able to do it yourself, there are plenty of specialists out there who will maintain a gun for you for a fee. You know it makes sense!

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