Idiots guide to classic airgun strips (pt 1)

[Phil Russell]

Haenel 303 strip and rebuild.
An auction buy in .22, this rifle falls into the medium springer class. Outwardly it looked good with no obvious damage. It shot fairly well but was only producing c. 400fps on the chrono so a strip was in order. This guide explains the basics of the strip plus a few tips but does not cover replacing the piston and breech seals as mine were in excellent condition. You will need a spring compressor to keep control of the action. You will also need a ‘pronged tool’ to insert into the compression tube and around the trigger unit in order to take the strain off the system when removing the mainspring.
I am aware that the design of the 303 changed slightly during its lifetime so this guide may not cover all variants; it will however, cover most issues.
Remove the stock: two screws at the forend and two in the trigger guard. There is a trigger adjusting screw in the guard but you do not need to remove this. When removing the stock, note the disc sitting in the underside of the stock in the forend. This is to prevent the cocking arm rubbing on the wood. Do not lose it. Some variants have a spring under this disc. Mine did not. Note the spring fitted to the end of the safety bar; the cocking link nudges this spring to automatically set the safety on cocking.
With the action on the bench on its side, barrel to the left, note a plastic endcap housing the safety catch. Remove the pin through the end cap then turn the safety catch through 90 degrees and pull the end cap and safety away from the action. Turning the catch like this allows it to free from the safety setting bar that sits on top of the trigger housing.
In front of the trigger is a large disc with a bolt head on top. Remove the disc and lift the safety setting bar over the trigger. Do not lose the spacing washer. You will note a small flat plate in front of the trigger and under the safety bar. This plate forms part of the mainspring retention system. On my rifle this plate came away with the safety bar, leaving the mainspring retained only by the trigger pivot pin. So if it appears firmly fixed, do not remove it before placing the action in the compressor.
Place the action in the compressor and insert the pronged tool into the end of the cylinder. Tighten the compressor to just take the strain of the mainspring. Now remove the small plate and the pin that goes through the action and the trigger unit. Juggle the compressor setting until this pin can be removed easily and let your drift pass through the action to keep the trigger in place. With the pin removed, grip the trigger and its spring so as to prevent the spring pinging away and pull your drift out. The trigger plus spring will come free. Note that one end of the spring has a long leg that fits into a groove within the trigger sear. Release pressure on the compressor and the mainspring and guide can be removed.
The articulated cocking link will slip away from the slot in the piston without having to split the action at the breech. The piston can now be removed, examined and repaired as required.
This is a good time to examine the plastic pad held in the cocking arm; it prevents the arm rubbing on the underside of the action. It had worn down on my rifle and some rubbing was evident. The pad can be removed by simply levering it out. I made a new one but it would be possible to shim the old one so that the plastic surface was just above the cocking arm edge if needed.
The mainspring fitted was a replacement (22 cm long) and as the piston and breech seals looked fine, I assumed it had gone soft so prepared a replacement from a standard Meteor spring. Initially I cut it with two extra coils but this was a mistake as it became coil bound. I found that the 22cm length was the critical length ... any longer became coil bound.
Reassembly is a reversal of the process: add piston, spring and guide. With action in the compressor and using the pronged tool, compress the spring and guide until the slot in the guide that the small plate under the safety bar fits into lines up with the cut out in the action. Replace the small plate. The holes in the action cylinder that take the trigger pin will now be lined up with those in the guide sides. You can now refit the trigger. Initially I did this before fitting the trigger spring as it was easier to align the holes in the trigger mechanism with those in the action. Tip: use a small screwdriver to hold the sear in position in the trigger unit as you replace the unit in the action. I used a drift to fit the trigger first then tapped the pin through, knocking the drift out on the way. You then need to fit the trigger spring. Locate the leg on the spring in the groove on the sear and the spring on the peg on the trigger unit. Then compress the spring to fit the end over the small peg on the action. A bit fiddly.
Alternatively you can fit the spring into the trigger unit and then locate the end of the spring over the peg in the action as you lower the trigger into the action. You need to compress the spring as you do so, keeping a firm grip of it between thumb and finger. By looking through the holes in the action you can easily see when the trigger unit is correctly positioned to allow a drift to be inserted to secure the trigger in place. Then add the pin, knocking the drift out in the process. With the pin and plate securely holding the mainspring, you can remove the action from the compressor.
Add the safety bar over the trigger. Make sure the spacing washer is in place within the safety bar slot and add the disc/bolt. The safety bar should slide back and forth quite nicely. Take the safety catch and end plug and replace into the action, making sure the safety catch is at 90 degrees to allow the catch to enter into the cut out in the safety bar. Secure the end cap with the pin. You may need to rotate the end cap in order to align the holes to allow the pin to be inserted.
Replace action in the stock. I found it wise to keep the trigger pulled as the trigger guard and trigger adjuster was replaced; this keeps the trigger out of the way of the adjuster until the guard is fitted.
And now a tale about the mainspring. Having replaced the mainspring with one of identical length and specification I found no change in performance. Remember that my spring was c. 22 cm long and verging on coil bound. I began to cut the original spring back just to see what effect it would have. Having removed about three coils to give a length of c. 19cm I was delighted to see that performance increased by about 70fps to give me an output hovering on 8 ftlbs. I can only suppose that a previous owner had tried to increase performance by adding a longer mainspring; an action that backfired somewhat.
Cheers, Phil

[Phil Russell]

PHOENIX MK1 STRIP AND REBUILD

The rifle was serial number 0015, purchased at auction some time ago. It seemed airtight when bought but when tried about 18 months later, it gushed air. This account tells the story of the strip and subsequent rebuild, except that I did not manage to remove all the air valve.
Do not worry, there are no parts that leap into oblivion when you start taking it apart, except possibly the hammer spring and adjuster if you are careless.

I work with barrel to my left. Remove air bottle. Remove the butt; one bolt through the pistol grip and the forend, 2 bolts. Remove the hammer adjustment bolt and spring from the end of the action; 2 grub screws hold it in place. Take care it does not eject when you release the screws. Lift out the adjuster and spring. The hammer should now slide out. Undo and remove the 8 bolts holding the barrel and loading probe assembly onto the main action. Lift the barrel etc away, taking care not to damage the transfer port which will remain in the action body. Pull the transfer port out together with its O ring and place it somewhere safe. Remove end caps on the safety catch. From the start it was obvious that a previous owner had taken it apart. One of the screws (2mm allen key) holding the safety catch was rounded off and had to be removed another way ... I drilled a shallow 3mm hole and lightly tapped a star bit in the hole. The screw came undone quite easily. Undo the 6 screws holding the body frame to the interior blocks ... 2mm allen head screws again.
As you release the 6 body frame screws you may note the two halves of the interior block begin to separate. This is quite OK. Carefully slide the action body parts up and out of the frame. As you do so, the main trigger sears will separate; one attached to the hammer housing (closest to the front of the rifle) and another to the valve housing block. Do not worry, they slide back together quite easily. Lift the 2 body parts out. On my rifle I found a small nylon washer sitting between the sears ... it had clearly migrated there during a previous strip as it should have been, with its partner, on the hammer housing sear pivot pin. Both were missing. The valve stem is now visible, protruding from the left hand end of the brass valve body in the valve housing block. To remove the valve it is first necessary to remove the two threaded dowels; one each side of the valve assembly. They are threaded 3mm and to remove them you need to screw a 3mm bolt (e.g. from the barrel assembly) into them and pull out the dowel. I made a simple puller from suitable washers which pulled the dowel out as I screwed the bolts in. This releases the brass valve end cap. Unfortunately on my rifle this is as far as I got as the main valve body containing the valve head remained in the rifle and it did not move with a slight pull on the valve stem. So I left it. If anyone knows how to remove all the valve body, please let me know. I did remove, clean and replace the two O rings I found there.
As I could go no further, I reassembled the valve end cap and started to rebuild the rifle.
Reassembly is basically a reverse of the strip but the following notes may help. Check to ensure that the trigger guard bolts are not protruding into the bottom of the frame. My rifle had clearly had replacement bolts fitted and I found that a bolt that protrudes may interfere with the sears.
You can assemble the two housings held together or separately. Separately is easier, starting with the valve housing. Move the underlever down while entering the housing into the frame and secure it with the 4 screws. Then feed the hammer housing into place, making sure the sear of the valve housing passes into the channel in the hammer housing, not into the circular hole that takes the hammer. Also ensure the sear on the hammer housing passes below the valve sear so that it is against the bottom of the frame. Feed the hammer housing up against the valve housing and secure it with the two screws. Add the hammer, narrow end first, into the end of the hammer housing, followed by the spring and the adjuster. Holding the action frame firmly ( I did so vertically with the air filler on my knee), push in on the adjuster until the central groove is level with the 2 grub screws and tighten them to hold the adjuster and hammer assembly in place. Now return the underlever to the rest position, you should get the feeling of cocking the action against spring pressure. Pull the trigger; hopefully it will fire.
When I did this on my rifle it would not cock and it took me a long time to puzzle out why. Initially I suspected a trigger issue even though I had not disturbed any settings. Stripping the trigger parts to clean and inspect them was straightforward ... they are held by cross pins that have nylon washers on them. One pin holds the sear bar (about 2.5cm); removal of the pin allows the bar to come away with its spring. Refitting is easy; just ensure the spring locates on its peg. Putting the nylon washers back on the pin was the most fiddly part. Removing the trigger is similar although you will need to push the underlever pivot pin out to remove the trigger. Note there are black plastic washers on it. Again, make sure the trigger spring is seated correctly when replacing it. The nylon washers are again fiddly but a dab of grease to keep them against the housing while you tease them into position helps. I was missing 2 nylon washers but made some by slicing some off suitable nylon tubing.
The solution to my non-cocking issue lay in that nylon washer I had found during the strip plus the fact that the person who had stripped the rifle before had clearly not assembled the small leaf spring on the hammer sear correctly. The spring needs to exert force against the hammer sear bar which then pushes against the bar from the valve housing and was not doing so sufficiently. The spring had a slight curvature so I reversed it and all was well. Presumably the presence of the nylon washer between the sears just gave the extra pressure needed to allow intermittent cocking before I stripped the rifle.
Having done this I carefully screwed an air bottle into the filler until it started to vent air from the transfer port hole. I had been advised that this may well blow away any dirt and allow the valve to seal again.
I reassembled the barrel housing, taking care that the transfer port and O ring was back in place and that the loading probe spigot located in the hole in the bar of the underlever.
Then put back the safety catch end plugs and screws. Note that the safety catch is reversible. Just remove the spring from the side of the action ... one screw; and reassemble the other way round.
I was delighted to find the rifle held air when I tried it. The air blast must have done the trick although I am still puzzled as to how the valve body comes out. I test fired a few shots then resorted to a short chrono session to set the power as required by the adjuster. While doing this I found that at the end of a magazine and with the magazine removed, it is not necessary to ‘dry fire’. With the underlever in the down (or forward) position, simply pull the trigger and bring the underlever back to rest. The mechanism does not then cock and there is no need to dry fire.
I think I will have to live with the breech O ring. A later rifle, but still MK1, has a larger plastic ring fitted in the action, not a rubber O ring; or maybe there is an O ring underneath it. No matter, it seems I will just learn not to dry fire without a magazine in place.
I am also looking for some of the small star washers that fit on the ends of the pins on the underlever assembly. Two of these fell away, presumably broken (a tab missing) but just held in place when I refitted them. They are quite narrow in outside diameter and none of my supply of such items for the pin diameter was small enough.

Phil Russell

[ggggr]

I've been meaning to do this for a while except I had a problem (more later).
The pistol is one of those designs that the trigger mechanism is really better off being left alone other than a bit of a scrub with some cleaner (meths/isopropyl alcohol) and then some lube. This is partly because it would be very fiddly and partly because you cannot get spares.
Firstly I removed the rearsight by undoing the 2 cap head screws on the side of the sight and lifting it off the grooves.
Mine did not have a silencer on it and I did not have the special tools that I think the gun came with. I used a flat headed screw driver to undo the barrel and it came out ok.
I then pushed the button on the RHS that you use when cocking the gun. This lets the cylinder spring up a little from the trigger and grips. If you undo the forked nut on the grip/cylinder pivot, the pivot screw will come out and you can then slide the grip back a little and lift the cocking arm out of the cylinder. Put the trigger and grips to one side. The sear is in a little housing welded to the cylinder and is a simple thing with 1 pin and a coil spring. Remove the pin and the sear and spring slide forwards and out.
You should now have the cylinder, end caps and shutter mechanism left. There is a plain circlip holding the end cap/loading shutter--it was a bugger to get out. I managed by grinding a small screwdriver so I could get at it. TIP when I got it out, I ground either end of the circlip so it had a "lead in" to make it easier if it needs doing again. The endcap/loading shutter then came off and the little shutter/transfer port thing lifted off the end of the cylinder. There is a flat section circlip in the endcap,which opens and closes the shutter when the endcap is twisted.
I then wanted to remove the inner endcap from the cylinder to get at the piston. IT WOULD NOT SHIFT I tried Plus gas, tried to make up a tool like the proper peg spanner etc but it would not shift. I sent it to Mick T20 who managed to get if off without damaging it. nut sure whether he made up a peg spanner or a soft bush to grip it.
Anyhow, with this off, the piston, mainspring and guide came out. Clean and lube everything and go to part 2

[ggggr]

On the piston, there are 2 grooves of different depths at the front. Mine only had 1 O ring in the front but I decided to try to fit another thinner section one in the 2nd groove. not sure if it should have one or not. EDIT--- been told that some had a felt ring as an oil retainer.
I screwed the barrel back into the cylinder and then slid the guide and mainspring over it. The piston then went in. It sticks out of the cylinder a little but when you put the inner endcap on, it screws in easily enough. I put a tiny bit of THREAD LOCK on the cap and nipped it up with my crude and weak home made peg spanner (a bit of flat bar with two holes in it and 2 steel pegs). I then slid the plain circip onto the inner endcap so as to not have to stretch or force it over the outer cap later. I located the shutter onto its hole in the cap (middle one of the 3)and moved it so it was in the open position (ie you could see the end of the barrel). If you have not had the flat circlip out of the outer endcap, I assume it would go back in the right place. If it does not close the shutter when you screw the outer endcap up, try again with the clip moved round a little. With the outer endcap in position, you should be able to feed in the plain circlip to locate it.
You can now refit the sear,coil spring and the sear pin. I used a punch to line up the holes.
Get your trigger mechanism/grips and slide the cocking arm into the slot in the cylinder. Replace the pivot pin and nut. Push down on the cylinder and it should click into place on the grips. Replace your rearsight.

I've managed a quick plink with this between showers. It seems pretty accurate and not bad power wise. The trigger is a little heavy, but no worse than some other pistols. It seems a quite well made pistol.