In part two, Pete Evans looks at what’s involved in a routine service of a TX200
Pete Evans explains how to service your TX in your own home, with a ‘master kit in a tube’ from Air Arms
Last time, I took a look at the impressive TX family of rifles, concluding that there really was little to improve upon because most of the work that applies to other rifles has already been addressed at factory level. However, even a throughbred rifle needs a service from time to time to ensure that it remains at peak performance, and your TX will be no exception. Thankfully, although advanced in design, the TX is one of the easiest rifles to strip, and an ideal start in the big world of airgun maintenance.
On occasions, it can be difficult to source parts for air rifles, particularly those out of production, and even if you can get them they seem to be insanely expensive. These issues will be of no concern for the TX owner, though because it is a current model so all necessary parts are available from several on-line sources. Although Air Arms do not usually sell directly to the public, they have made provision for their customers in the form of their master service kit, part number MSK3.
Whilst at the last Midland Game Fair, I spoke to the Air Arms customer and technical service agents, Sheila Cooper and Chris Kemp, and a more helpful duo I have yet to meet. They introduced me to the TX kit and it contains everything you need for the job, neatly contained in a tube.
I have never seen a kit as comprehensive as this, supplied by a manufacturer. Along with the components is a detailed instruction leaflet to explain the process step by step. There are only two things you need to know before purchasing the kit –the calibre and mark.
The TX has passed through three marks, and it’s important to distinguish between a Mk1/2 and a Mk3. The easiest way to do this is to examine the compression chamber from the right side of the gun. The Mk1 has no grooves visible because there is no anti-bear trap device; the Mk2 has three, equally spaced groves and the Mk3 has three grooves, but they are unevenly spaced.
STARTING THE OPERATION
No special tools are needed for the job – just a 10mm open-end spanner, parallel punches, and some hex keys.
Start off by getting the action out of the stock. You will find two hex-head, countersunk screws in the fore end and two hex-head bolts in the trigger guard. I do think that hex-heads are an elegant solution, I’m sure purists will disagree, but that’s my take on it.
When the action is parted from the stock, take a minute to comprehend the superb finish of the metal work, and the fit of the components. When you’ve taken your fill, loosen the 10mm stock fixing stud – make sure you simultaneously apply hand pressure to the back block. If the TX has a factory spring, there will be no need for a spring compressor because the spring has very little pre-load. If in doubt, get it in the sash cramp.
Once the lug is removed, the back block and trigger mechanism can be removed as one unit.
If the trigger unit is to be removed, drift out the two pins, taking care not to lose the safety catch and spring. If you look closely, you will notice these retaining pins have a rounded convex profile at each end. This carries through to the pins holding the trigger components. It doesn’t sound very exciting, but to me, it’s just another attention to detail by the Air Arms crew.
CAUGHT IN THE TRAP
With the back block off, the spring and guide can be slid out. The underlever link will need to be removed before the piston and compression chamber will come out. The underlever link is held in place by a pin which has an ‘E’ clip on each end – only one clip needs to be removed. This will lever out with a small screwdriver, but be careful because it is all too easy to lose. With the pin out, the underlever link will hinge up and can be detached from the cocking shoe, which acts on the compression chamber. Slide the cocking shoe toward the open end of the cocking slot and guide it out – be mindful to which way round it sits in the cocking slot. At this point, I would remove the underlever by drifting out its pivot pin.
The compression tube will slide back along with the piston, press the bear-tap button and
it will pass without hinderance, out through the back of the action.
I mentioned in part one of this article that the TX didn’t seem to have any inherent weaknesses, well there is one, which I have observed on a few occasions.
On the underside of the barrel you should be able to see a rubber buffer which cushions the closure of the underlever. I said ‘should’ because what you might see is a hole, or sometimes a hole plugged with rubber where it should be. It’s worth replacing this and whilst the underlever is off is a good time to do it.
The buffer is not in the service kit, but costs a few pence – it is part No TX227. As supplied, the buffer is too long, so clip it with a couple of mm of the thinner diameter tail protruding over the top of the thicker part.
Grip the end between thumb and index finger and screw the rubber shank into the hole. If you try to press it in, you could be in for a struggle. Thanks must go to Chris Kemp for sharing the factory fitting method.
With the compression tube and piston in hand you will have all the components that will need seals and bearings changed – it’s always good practice to clean everything before starting.
The piston seal can be levered off with a screwdriver, pushing the new one back into place. Hot water can make things a bit more pliable, if required.
Ring bearings will be found on the piston. Simply find the split, spread a little and slide off. Replace in a similar manner.
Transfer port seals live in the front face of the compression tube and consist of a pair of ‘O’ rings back to back. A pointed tool will soon have them hooked out.
A little smear of grease on the side of the piston seal, and a little on the bearing areas, and the piston can be slid back into the compression tube.
Before pushing the rebuilt assembly back into the action, make sure you press on the bear-trap release, else the compression tube won’t slide all the way in.
Slide the cocking shoe back into position, making sure it’s the correct way round, re-insert the cocking link. Make sure you grease the underlever pivot point before reattaching. Once in place reconnect the underlever to the cocking link with its pin and ‘E’ clip.
PLAYING YOUR CD
Air Drms fit the computer-designed (CD) trigger to their spring guns, which contrasts with the Rekord trigger fitted to the Weihrauch range. In reality, the CD does borrow from the Rekord in design, although it does differ quite considerably in function.
I will go on record here (no pun) and state that in my view, I prefer the adjustment set-up
“... satisfaction knowing that your gun is ‘right’. It’s a feeling akin to having a fresh service and MOT on your car”
on the CD, and also find it easier to strip. In use they are easily equal, both performing superbly, easily the best pair of triggers available on a spring gun.
Regular readers of my scribblings will have come to know that I am a fan of the Rowan range of triggers, particularly their extra-set-back design for the HW range. As luck would have it, they make a target-style blade for the CD unit, which has adjustment fore and aft, as well as being able to swivel so that it can be offset – it seemed too good an opportunity not to try.
To change the blade, start by drifting out the trigger retaining pin, before dropping out the trigger blade.
Before installing the Rowan unit, I like to ensure that both adjusting screws are just protruding from the internal face, then place the new blade into the mechanism and refit the retaining pin.
At this point, the trigger is completely useless because it is out of adjustment. I prefer to make most of the adjustments with the trigger mechanism off the gun for complete safety reasons.
Cock the trigger by pressing down the top sear until it engages. In small increments, screw in the first stage adjuster (screw furthest from the blade), until the trigger fires on the first stage only, it’s wise to keep a hand over the top of the sear to cushion its upward motion.
At this point, re-cock the trigger and slowly advance the other second-stage adjuster until you feel a distinct first and second stage, which seems to be to your liking. In practice, it is likely that you will need to repeat this process several times before getting it right – basically, its a balance between the two adjustment screws. When the trigger is fully refitted, you might have to tweak the adjustment a little, but at least you will be in the right ball park. The trigger itself comes with comprehensive instructions, but if in any doubt, ask your local gunsmith to take a look.
The adjusted trigger can now be fitted into the back block. Taking care to refit the safety button and spring, drift back the two trigger retaining pins.
BACK TO THE ACTION
The piston weight, together with a very lightly greased spring, can now be offered to the piston, followed by the spring guide. It will be noted that two washers are provided with the spring guide in order to give the spring a little more pre-load and hence power. At this point, I opted to use one and see how things went because it’s an easy task to add the other one if required. Be aware that power will increase as the rifle beds in.
Make sure the spring guide engages correctly with the back block (there is a recess there), and push down, whilst screwing the stock lug back into position.
All that remains is to replace the stock. Air Arms recommends tightening the rear trigger guard screw first.
FRUIT OF THE LABOUR
Give yourself a few shots to let things settle in before running the gun over a chronograph – the only accurate way to check performance.
In this case, I had a power hovering around 11 ft.lbs. with Air Arms Field, which to my mind is just about right.
There is definitely a satisfaction knowing that your gun is ‘right’. It’s a feeling akin to having a fresh service and MOT on your car. It is likely to instil confidence in the owner, which will pay dividends in the field or on the range. Do not underestimate the role that psychology plays in our shooting.
So, if you are a budding enthusiast wanting to service a gun for the first time, the TX is a pretty good place to start. That’s all we have space for this month, but I have more delightful airguns crying out for attention – wait, I hear one now! I think it’s saying SuperStar! I
Happiness is a home-serviced TX.
All the service parts you need in a tube!
Sheila Cooper and Chris Kemp displaying the TX master service kit.
Slide the cocking shoe to the widest point and lift out – check its position in the track.
Two fore end screws and two from the trigger guard – the beauty of this rifle extends beyond its skin.
Lever off one of the clips, make a mental note where it lands, withdraw pin releasing the link.
This 10mm bolt releases the back block; spring pre-load should be minimal on a standard gun.
Compression tube and piston coaxed out. Tap the piston upside down on the bench to get the piston weight out – it might be stuck with grease.
Lever off the piston washer with a screwdriver. Delrin bearings are split and easily spread and slipped off.
There will be two ‘O’ rings in here – a pointed tool helps them out.
Slowly screw in the first-stage adjuster until trigger releases, then slowly advance the remaining screw to balance and introduce second stage.