Idiots guide to classic airgun strips (pt 1)

[ggggr]

Replace barrel and barrel pivot bolt and the lock screw. You can use or make up a bit of shim so the cut outs in the bolt head line up with the lock screw. Replace cocking arm and its pivot and lock screw. Put action back in stock and tighten up stock screws. Replace sights.
I find these a very well made,robust gun and an ideal starter to strip. The only real problem on the British ones being lining up the trigger when replacing the pivot pin. The pistons are much better than the 22,s and I reckon if you have a decent piston and breech washer and keep an eye on the pivot screws,will probably not need doing again until you need a new mainspring. I think meteor springs will fit the 27 and are a touch "softer" although there is not much in it. If the trigger goes light, you can file or stone the trigger face square (and /or ) the piston rod face. You can also play with different bits of trigger spring to get a feel you like. Manchester Airguns used to sell lengths of spring for a few quid and this was ideal for playing with trigger and barrel plunger springs.

[ggggr]

I cant do links ---but if you check Richiet,s "webley mk 3 date " thread of 18/4/09 and see my post2 then that will do for most of it. Dont know about guide but strip is very easy ---take out of stock,take off cocking arm and under lever--Take breech plate off and remove tap. Take out trigger screws and then pins to remove trigger and sear--UNDO LEFT HAND tHREAD SCREW-Unscrew trigger block-- Remove mainspring and piston----(hard bit coming up) I think earlier ones had the piston washer rivetted on and later ones screwed---Sometimes,as on all guns with a countersunk screw holding on the piston washer, The screw gets battered and can be hard to remove, usually resulting in a damaged piston washer. If you are lucky then the washer will be in good nick. I think its pot luck---Ive seen some guns around 45 or 50 years old that the washer is okay on and others where it has rotted away, probably due to too much oil being put into the cylinder. I hope this helps.
Regarding putting the trigger back on these, its a "patience" job---One of those that will go in first time or spend 30 mins swearing at it. You put the sear in and locate it with the pin, then you put the trigger spring in and sort of have to push the trigger up and forwards to compress the spring a bit and locate the trigger pin. If the gun doesnt cock and you are sure the you have done everything right, remove the main spring and see if it cocks then ie. if the piston is coming far enough back. Sometimes the cocking arm has bent a touch and the piston rod is a few thou short of engaging. IF YOU ARE SURE THIS IS WHAT IS HAPPENING-remove the cocking arm and place either end on a block of wood, then place a smaller block of wood on the bend of the arm and give this block a sharp tap with a smallish hammer. This should cure the problem. NEXT UP ---WEBLEY FALCON ,then HAWK MK1


Re--the mainspring. Troubled shooter says " The original spring was: 9 ½" x 27/32" x 29 coils (24.2cm x 21.30mm) "
I found a spring that was 20.5mm Od and about 2.75mm thick wire. I cut it to the same length as the Webley spring and it is a nice, pleasant to shoot and easy to cock plinker.

[Ulverston]

Excellent...

[ggggr]

Remove rearsight. remove two front stock screws and the screw in front of trigger guard and remove action from stock. Undo cocking arm lock screw and pivot screw and remove cocking arm.Undo locking screw and barrel pivot screw and remove barrel. Small screw on left of breech block if you want to remove plunger and spring.Tap out trigger pivot pin and remove trigger and trigger spring (more in minute). Tap out sear pin and remove sear. The trigger bit you pull on goes into the bit that endgages on the sear and has a small pin securing it. These often wangle and I remove the pin and solder the two bits of the trigger together (making sure pin hole lines up)> you could try araldite but make sure pin holes line up ang you grease the pin or use paper clip till glue dries. On the left of the cylinder is a small 4ba grub screw. You need to remove this before trying to undo trigger block--The heads are often broken and you may have to try to tap it round with a small punch or grip it with long nose pliers. I had to drill one out and then retapped hole to 3ba. (screws and taps available from chronos etc and come in handy). Unscrew trigger block. There is not as much pressure as on a lot of guns. Keep pressure on until its undone and slowly release. GO TO PART 2

[ggggr]

Remove guide. spring and piston. Piston washer is leather and held on by a countersunk screw on a dished washer. The pistons on these can wear where the cocking arm pushes as the metal is quite thin. If you know someone handy they could probably mig weld where its worn and file it up. I have fitted a Diana 25 spring to one I did for my niece to give the gun an easier life and to make it easier for her to cock. Worth thinking about if you only plink. Every thing clean and lubed? Put piston, spring and guide back in cylinder. (sometimes you have to push edges of washer to ease it into front of cylinder where cocking arm slot finishes). Place piece of thick cardboard on a block of wood on floor and place breech jaws down. You should then be able to put pressure on and screw block into cylinder. The cardboard enables cylinder to turn so you can get a part turn with both hands! Replace small screw on side of the cylinder.Replace barrel and pivot and lock screws. Do same with cocking arm. Replace sear and pin then (as with mk 3 post above) replace trigger spring and push up and forward to line trigger and pin. Replace action in stock. Tighten the 3 screws and refit rearsight. WEBLEY HAWK MK 1 next

[ggggr]

The plastic rearsights on these are fragile so Id just be careful rather than remove it. Undo 2 front stock screws and one in front of trigger and remove action from stock. This rear screw can strip and Ive tapped them out to 1ba when they have, Ive heard of people putting a nut on the inside of the trigger housing but have not tried this. Sometimes this screw can push on the sear and stop the rifle from cocking. A washer under the head of the screw should cure this although Im sure you could grind away the underside of the sear. With action out of stock you can ondo cam and slide out barrel.(suggest you do this with breech open or you wont be able to get to barrel plunger later) You can take circlip off cam and remove cam to grease up. Remove roll pin in cocking arm and remove arm. Depress barrel plunger and remove pivot pin and then plunger and spring to grease up. Flick the two circlips off the trigger pins (noting how trigger goes) and remove pins and then trigger,trigger spring. safety catch and sear and sear spring. I find with hawks its easier to place encap on piece of wood and push down on the breech end and remove cylinder end pin. GO TO PT 2

[ggggr]

Its worth noting that this hole in the cylinder can stretch when big springs have been fitted. Im sure there are people on here who can weld them up and redrill but just dont fit a powerful spring. Meteor springs seem a better fit in hawks than hawk spring Ive tried recently and the Diana 25 spring remains a soft plinkers option. Release pressure on cylinder and end cap and mainspring should come out. Ease piston out. These had a ptfe washer rivetted on (Nibbs sells them ) But I prefer a leather one held by a screw and nut. SEE THREAD "hawk mk 1 info" post 13 by DCL DAVE. Thats the sort of thing I did. Lube up and put back together. Piston in and then mainspring and push down on cylinder the same as in stripdown to replace end cap and pin. Place sear and searspring on safety catch and slide into housing,locate,put pin in and circlip on. Fit trigger spring onto trigger with long leg behind trigger and locate,pin and circlip. (if your cylinder pin hole is worn and cap is a little off the cylinder, you may have to use a piece of shim steel to cover the gap to stop trigger spring going into it whilst you are replacing it. Replace cam in breech and replace circlip. Replace barrel and secure. GO TO NEXT POST

[Jamie Norton]

Use a digital camera to take pics of the components (especially trigger assembly) BEFORE you dismantle them. Referring to the pics on reassembly could save you headaches

[Phil Russell]

I forgot I had written these notes: they may help. All is pretty straightforward except getting the trigger / safety back together which is a bit of a fiddle until you get the knack. All is explained here:

CROSMAN 766 STRIP

Taking apart.
Remove barrel band (2 halves, single small screw goes though band)

Remove barrel band ends: plastic, lifts away.

Knock out the pin holding the pump lever to the pump tube.

Remove pump lever with pump attached.

Remove barrel: hex key on top of action.

With the breech block on its side, screws uppermost, stock to the right, remove the 4 screws. Keep top plate in position while doing this.

Gently prise the top plate off the bottom plate. Take care the pump handle plastic grip holder, black plastic sprung laden bit on left, does not ping out as you release the top plate. Top plate may come away with the trigger and safety catch or may leave trigger and safety in the bottom plate. Either way the trigger safety spring may become detached from its location on the safety. Do not worry. Remove trigger, spring and trigger pin.

Note position of trigger sear components.

Lift sear away, taking care not to lose the large spring that acts on the sear bar. Lift off the long spring and plastic peg that acts as the BB follower from its channel.

The valve housing is held by a screw to the left of the valve housing. Before releasing this, note the brass component at the top of the valve body towards the left. This has a small spring over it. Release and remove the screw holding the valve housing but hold the housing in position. Now gently lift the housing away to the right, catching the small spring on the brass piece and also noting that the striker piece and a black plastic end body will be released under spring pressure on the right hand side. Just go slowly and this component will not be forcibly ejected. The brass valve body will slide out of the air cylinder. If it is an easy, loose slide then inspect the O ring as it will most likely be worn.

If needed, replace O ring.

Clean all parts, especially the air cylinder.

I have not dismantled the valve.

Rebuilding
Reversal of above but these tricks may help.

Assemble valve body and housing into place in the air cylinder. Have the brass component in place but do not fit spring yet. Take care that the striker and its spring and the black plastic end cap are located correctly. Replace the screw to hold the valve housing.

Carefully replace the small spring over the brass component. There is just enough room to wiggle this over the component; it stays in place against the bottom plate.

Refit trigger sears in place and slip the sear spring into place.

Refit the pump handle retaining spring and catch ... take care it has a habit of falling out.

Refit the trigger and its rod with the safety spring under the trigger and the hooked end pointing up. At this stage I found it best to hook a small bit of thin wire over the long arm of the spring and feed it towards the trigger such that when the top plate is replaced it protrudes out of the trigger guard.

Replace top plate: a bit fiddly to do this and keep pump handle spring in place but persevere.

When located, pull on the bit of wire to pull the safety spring long leg downwards ... look through the hole for the safety catch to see if it has cleared the hole. When it has, feed the safety catch back into place and release the spring. Pull the bit of wire out.

Replace 4 plate screws.

Refit barrel, and pump etc.

Job done.

Cheers, Phil

[Phil Russell]

It is a long time since I serviced a Challenger.... it was in .177 and I later sold it, a decision I now regret. An opportunity arose to look at a .22 version and, as they are a little different to the standard Mercury, I thought a separate entry was justified:

This is basically as for the Mercury but with a few differences. The Challenger has the Maxigrip scope rail ... a raised rubber rail fitting to the top of the cylinder by lugs. It also has an articulated cocking link.
To strip, remove stock bolts at front of action and the large bolt through the pistol grip, just as for the Mercury. Remove front and rear sights for safety. Remove trigger block by unscrewing the unit as normal. I secured the action in a rubber faced vice to start the thread moving then put the trigger block in the vice and unscrewed the action as it gave better control. Spring and spring guide will lift out. My rifle had a thin washer on the spring guide. My breech seal was OK so I left it alone. Otherwise now is a good time to renew it.
With trigger block removed, get a piece of wood and place it against the edge of the scope rail ... tap it to drive the rail backwards about 1cm when it will lift off. Note that it is not possible to remove the piston until the scope rail is removed.
To remove the piston you need to release the cocking link. You could release the connecting pins or the barrel from the breech but I found it easier to remove the two bolts holding the cocking slide and lift it away, noting that there is a thin steel sheet floor to it next to the cylinder. This leaves the linkage attached to the barrel breech but I found this perfectly OK.
It is now possible to release the cocking link and pull the piston out. It has the standard O ring plus buffer washer system on an aluminium piston head. My buffer washer had disintegrated. To put a new one on, find the thin (about 1mm diameter) pin that holds the head to the piston body and push it out enough to release the head. At this point I took the opportunity to clean up the head (with O ring removed) as it was a little rough in places and also smoothed any rough edges off the piston body. Renew the buffer washer on the piston spigot. Replace thin pin and add or renew the O ring ... mine was OK so I refitted it.
Clean the cylinder, lube the piston and O ring and push back into the cylinder. I checked compression with my thumb over the transfer port. All was OK.
Replace the scope rail now. Press the rail into position using the imprint left by the rail after removal as a guide ... again use a wooden block to help tap the rail into position. Make sure all the scope rail lugs engage and that the end of the rail is flush with the end of the cylinder or you may have difficulty refitting the trigger block.
You can now replace the cocking link in its slot followed by the slide, not forgetting the thin sheet base ... note the lugs that fit in cut outs on the slide. Tighten the two bolts.
Replace spring (thin smear of moly grease) and spring guide and washer.
To refit the trigger block, I held the block in a padded vice and offered up the action. I have a small block of wood with an indentation in it that takes the muzzle. With the block over the muzzle and holding the cylinder in position with my left hand, I push the wooden block with my right hand until the cylinder engages the threads on the trigger block then turn the cylinder with my left hand .. it moves easily due to the muzzle being in the wooden block. Continue to screw the action to the trigger block making sure the block ends up in line with the cocking slot.
Replace stock and sights. Test.

Extra notes on the barrel / breech jaws: If you split the barrel from the breech jaws by removing the cross bolt, note that this bolt also secures the barrel lock plunger. When re-assembling the assembly you need to place the breech block between the jaws with the through bolt hole lined up, then press the plunger in about 3mm in order to allow the bolt to pass through. I press the plunger against a wooden block while holding the action and feeding the bolt through.
The breech seal: This is 12mm od and 8mm id x 4mm. New ones can be cut from urethane tubing 12mm x 8mm at a fraction of the cost of buying new.

Cheers, Phil

[Phil Russell]

DIANA Mod 27

Note: this is the Diana 27 not the Diana G27.
This rifle has a variant on the ‘3 ball trigger’ as used on larger Diana/Original models. It should not, however, give any problems during the strip and rebuild but I recommend use of a spring compressor in order to keep control of everything.
To strip: Remove the two bolts at the forend. Remove front trigger guard bolt and remove action from stock. Remove sights. Remove action end cap (just pull off).
Look at the action ... note the smallish cylinder coming out of the back and the small spring on the underside top of the action that fits into this cylinder.
Secure action in spring compressor, barrel to left and trigger uppermost. Using the compressor, just take the strain on the protruding cylinder. There are two cross pins; remove them both with suitable sized drifts. Slowly release tension on the spring compressor... the inner cylinder will begin to be pushed out by the mainspring.
As the inner cylinder comes out, keep the trigger pulled. There is no need to remove the trigger blade or its pivot or spring. The inner cylinder will come out along with a surrounding metal sleeve onto which the front end of the small spring rests. Once the mainspring tension has been released, lift away the small cylinder and sleeve ... the small spring may well come loose at this point and the spring guide may remain attached to the front of the small cylinder. Try to keep the small cylinder within the sleeve until you have the parts safely in hand.
Separate sleeve from small cylinder and note the 3 ball bearings in recesses in the small cylinder. Note which way round the parts fit and clean them. Note that the outer sleeve has a cut out for the rear cross pin not distinct holes.
Remove mainspring.
Release the cocking link from the breech by removing the lock screw and the pivot bolt. Remove link and detach from piston.
To remove the piston, simply slide it out but pull the trigger to allow it to pass freely.
Inspect piston washer and replace if necessary. The breech seal on this rifle needed replacing. I made one from leather 3mm thick, 13mm o/d, 8mm i/d. You may be lucky and be able to remove the old seal in one piece and add a shim to take up wear. This rifle already had a thin sheet steel shim but the seal fell apart during removal.
Once everything is cleaned and rough edges removed, rebuild is a reversal of the strip.
Replace piston in cylinder, correctly lubed. Remember to keep trigger pulled during replacement. Replace cocking link. Add mainspring and guide.
Replace action in the compressor as before.
I now added the balls to the inner cylinder after placing grease in their location holes. Then insert the cylinder into the sleeve. The small spring will fit into the long slot on the inner cylinder with the forend (nearest barrel) of the spring fitting against a depressed tang cut out in the sleeve and the rear end of the spring fitting against the end of the cut out slot. You will soon see which way is correct as the trigger slots must face the trigger sears and this tang goes against the top of the action. Do not add the small spring yet unless you are confident of keeping it all together.
Hold the small cylinder and sleeve in position on the spring guide and start to wind them into the action a little. This is the time I refitted the small spring. I turned the action through 90 degrees in the spring compressor so that the trigger was pointing at me. Locate the small spring against the cut out in the sleeve and compress the spring to locate the rear end in the slot in the inner cylinder. Compression is not great and once fitted it should remain steady. Continue to wind in the mainspring. Make sure the spring guide fits over the piston rod ... if you meet sudden resistance while starting to wind the spring in, then you need to back off and jiggle the guide over the piston rod.
As you wind the unit in, the sleeve will also move in but keep checking that it is moving in fully by pushing it in with a screwdriver blade and keep checking the trigger is not impeding movement by pulling it. If the trigger feels stiff, back off and pull trigger. Wind the small cylinder in until you can see the locating holes for both cross pins. Replace cross pins and end cap.
Replace action in stock and add sights.
Cheers, Phil

[Phil Russell]

FALKE MOD 70

A well built rifle that is straightforward to strip. But beware of the spring preload; not excessive but be prepared.
To strip: Remove two screws at the front of stock. Mine were 4mm thread. Remove front bolt from trigger guard and lift action from stock, leaving trigger guard in place on the stock.
Note the large ‘bolt’ at front of trigger housing; the front stock screw fastens into it. This secures the trigger housing position to the main cylinder and must be removed before you can unscrew the complete housing from the cylinder. I clamped the trigger housing in a padded vice, trigger uppermost, and unscrewed the action from the housing, wearing a thick leather glove on my right hand. Take care when you see that you are close to the end of the thread as the action will release suddenly under the tension of the mainspring. Remove mainspring.
I had no reason to dismantle the trigger mechanism but it looks as if there is just one cross pin holding it in place.
To access the piston, remove the barrel and cocking link assembly as a unit by removing the barrel pivot lock screw and then the barrel pivot bolt. Separate the barrel from the breech jaws, catching the barrel release catch as you do so. The cocking lever will lift out of the piston cocking slot and is just slid out of the cylinder housing. The piston can now be slid out of the cylinder.
The piston washer on my rifle was leather and in good condition so I did not dismantle the piston head. If needed, it looks easy to do with a conventional centre bolt and washer holding the piston washer to the piston body. I cleaned all the accumulated gunge off the piston washer and piston body and smoothed away some rough edges. I did not make a piston sleeve but did add a steel washer inside the piston to act as a spring bearing.
Clean inside the cylinder if needed.
The mainspring looked OK .. 235mm long, 3mm section x 21mm diameter. I do not know if this was original spec but as it looked Ok I re-used it.
To reassemble, lubricate and add piston to cylinder. I used a few drops of SM50 on the piston washer and a light smear of moly grease on the outside of the piston body. Add spring, light smear of moly paste again.
To refit the cylinder to the trigger housing, I clamped the housing in a padded vice and screwed the cylinder onto the housing. I did this before refitting the barrel assembly. To help do this, I used a block of wood over the breech jaws: this gave a much better surface to push on to compress the spring and allow my left hand to turn the cylinder to start the screw thread. Screw the housing and cylinder together and finally secure with the large bolt. Feed the cocking link into the piston slot, place barrel release lever in place and fit barrel into the breech jaws. Secure with bolt and lock screw. Refit action into stock.
Basically, that is it. The sprung barrel plunger was OK but if you need to remove it, there is a simple cross pin that holds it in place. The breech seal was leather and looked easy to replace if needed.
After this simple service our .22 rifle returned 525fps with AA Field and 535fps with Superdomes.

Cheers, Phil

[Phil Russell]

Here is my simple guide for anyone wanting to take this rifle on. I approached it almost blind but did have a picture of the valve assembly from an Indonesian webpage. It is quite straightforward and the only tools needed are screwdrivers and a needle to remove a seal and twiddle parts into position. You will need a narrow shank screwdriver to access the cylinder to barrel screws. I am afraid I did not record the O ring sizes I used but all came from either a cheap small variety (about £1) box from a tool shop/discount store or from a larger set of around 300 rings available for about £10 from tool shops.

SHARP PAN TARGET (and Victory)

These notes refer to the Sharp Pan Target pneumatic rifle but as the action is basically the same as the Sharp Victory model they will be of help should anyone wish to strip and reseal that model.

The rifle in question would only fire at around 400fps (.177) no matter how many strokes of the pump were used. There was an initial hiss as the air entered the inlet chamber on stroke one but no hiss on subsequent strokes and the pump lever would move easily to the open position on its own. My diagnosis was that air was escaping back from the inlet valve into the pump compression tube.

As always, put all small bits in a safe container. Remove sights. Remove action from stock: 1 bolt in forend and the 2 trigger guard bolts. There is no need to remove the trigger guard if it is firmly held in the stock.

Remove pellet probe by removing the 2 small bolts in the small plate on the lh side of the breech and then remove the larger bolt that is underneath. Take care ... hold the probe as you remove the bolt as the probe is sprung laden. Note that this bolt has a square end where it fits against the pellet probe.

Remove trigger unit by undoing the single large bolt at the rear of the trigger. Remove the trigger unit, taking care not to lose the spring that sits underneath it.

Look at the rear end of the compression cylinder ... note a plug with 4 small holes in it. Unscrew this. You may be lucky and find it only finger tight or you may need to use a tool. I used the prongs from a pair of circlip pliers. Remove the plug complete with spring and probe.
Look inside the end of the compression tube and note a small cylindrical bit with a hole in it. Wiggle this out of the tube through the adjacent hole in the cylinder (the spring under the trigger unit pressed against this part).

You can now see the valve assembly in the compression tube but cannot remove all of it before removing the barrel.

It is easiest to remove the pump lever now. I did this without splitting the lever handle away from the link arm. Undo and remove the screw in the end of the compression cylinder near the arm pivot. Remove the threaded insert that this screw passed through. Remove the end plug ... again it has 4 small holes. With this out of the way it is possible to fold the pump arm against the body and gently tap it towards the front (remove plastic handle first) to knock out the interior plug and reveal the pin that the pump arm swings on. Remove the pin and then push the interior plug and arm back into the cylinder so that you can free this end of the arm. Remove the interior plug. Now fold the arm over and push the compression piston towards the end of the cylinder ... it can protrude enough to allow you to remove the next pivot pin. Pull unit back into the tube and remove the complete pumping arm assembly. You can now pull the pump rod and head assembly out of the front of the tube.

You are now left with a cylinder with barrel attached and the valve system inside the cylinder. Look through the hole in the pellet probe housing about half way along . You will see a bolt that connects this end of the barrel to the cylinder and valve. Remove this bolt. A light tap will now release the rear (pronged) part of the brass valve assembly into your hand but leave the main valve in place. Remember which round it is. This end of the barrel is now free.
To free the barrel there are 2 more screws accessible though holes in the underside of the cylinder ... one about 5cm back from the front of the cylinder, the other about 18cm back. You unscrew the screws by inserting a screwdriver through these holes. The screws are quite small but are visible through the slot in the cylinder that the pump arm moves in. Take care ... as you release the barrel it will come away and release the plastic padding strips. Note that there is a brass washer/guide in the strip near the breech. The cylinder will have the transfer port attached and will most likely leave the port seal in the barrel recess. Put barrel on one side.

The transfer port screws into the cylinder and valve assembly ... remove it carefully. The main valve is now ready for removal. I had to use a dowel to push the assembly out of the rear of the action. It is sealed with an O ring.

Once free, split the valve assembly by unscrewing the front from the back. Remember that the front has the O ring. The rear (exhaust) assembly comes away easily to reveal the valve head, spring and plunger. Clean all components. I needed a new valve head seal ... the old one was a rubber insert press fitted into the valve head unit. I made a new insert using a 3/16” disc cut from a water cistern valve sealing washer. Replace the O ring inside the rear assembly through which the valve stem passes.

The front part of the valve (inlet side) may have remained as one piece. To service it, prise out the large seal you can see inside the valve and release all components. Note the order. Clean everything. There will be a valve stem plus seal ... replace this seal. I used an O ring even though the seal looked somewhat domed. Replace the other small seals with O rings. Rebuild the unit. The large main seal you prised out may have been a square section one but I replaced it with an O ring. Replace the exhaust assembly onto the inlet housing... don’t forget the plunger. Check that the entry valve works on its spring and that the exhaust valve can be pushed in against its spring.

It is now time to put it all back together. This is really a case of just working back through the dismantling procedure but there a couple of points to note.
When replacing the valve assembly in the compression tube remember to lubricate the sealing O ring as you push the unit into place. It will be a tight fit, as it should be. Remember to push it in with the transfer port hole correctly aligned with the top of the cylinder. Pushing the valve in is complicated by the protruding valve stem ... use the pronged part of the valve assembly to help push. Leave this part in place with the holes correctly positioned.
Now replace the barrel. I found it easiest to fasten the long bolt through the barrel breech housing into the pronged valve part first. Just replace the rubber buffer at this end (I think the rubber buffer is profiled so make sure it is the right way up), making sure the brass washer/spacer is correctly located and nip the barrel into position. Now add the rubber buffer at the forend and replace the other two barrel retaining screws. They are fiddly to fit so I use a pair of tweezers through the pump slot to hold them in place. Make sure all is nice and snug.
Refit pump arm (lubricate the head with a suitable lubricant; I use Pellgun oil) ... fiddly but persevere. Add the ‘small cylindrical bit’, prong end first and to the left of the breech. Screw in the end plug assembly, making sure the rod part goes through the ‘cylindrical bit’. You can check all is OK by looking through the trigger housing hole ... you should see the exhaust valve rod and the cocking rod. Refit the loading probe; push it all the way with the cut out facing left, then add the screw with the square end. Too tight will impede movement so get it just right.
Refit the trigger unit, making sure you add the spring between the unit and the ‘cylindrical’ bit. Check that the cocking button cocks the trigger and releases the loading probe and that the loading probe will lock forward again. If it does not work, remove trigger unit and end plug and turn the ‘cylindrical bit’ a half turn. Refit. Check again.
When all seems OK, replace the small cover over the pellet probe screw and refit stock and sights.
A quick test showed that air hissed in on stroke 1 and again on stroke 2 and 3 with a healthy crack when fired. Success. I put 4 strokes in and found the fourth very hard going. I clearly need more porridge.
I have some pictures of the valve etc so if you need them, just ask.

Cheers, Phil

[RayB]

Interesting reading RayB

[Phil Russell]

Here is a dismantling procedure for the Park RH93. I fully expect it will be OK for the RH91 as well as the only difference, I think, is the safety catch on the RH93. I found the procedure while searching for information and post it here with the permission of the original author (dvd).


Park RH 93 strip-down.
This is for those who have one of these unusual airguns and would like to know a thing or two about stripping them.

Dismantling procedure:

Please observe all safety requirements. Keep all parts removed from the rifle, in a well ordered sequence, to aid assembly later.

Remove the woodwork from the action by undoing the two fore-end screws and one on the trigger guard.
Grip the action in a well-padded vice. I use old cotton T shirts folded without any lumps to grip the metalwork evenly, and remove the trigger as a unit by removing the retaining pins and circlips.

With a suitably shaped piece of hard-wood so as not to press directly on the safety tab, and using a little bit of pressure from a spring compressor, push the end plug just enough so that the retaining cross pin is not under tension and it can be pushed out using finger pressure.
The spring compressor is then released slowly and BEFORE the end plug is fully free of spring tension, care is taken to CATCH the safety return-spring and guide located in the end plug, which bears against the upper side, inside the cylinder.
Once the plug is fully withdrawn, the safety tab assembly, spring assembly, and cross-pin are taped together to avoid losing the small bits.

Using a suitable packing piece, compress the rear piston till there is enough slack in the chain to remove one of the two links, that which is situated on the exposed part of the chain. (i.e. cylinder front end.)
When this link is removed, slacken the compressor and remove it from the action.
Remove the other link from the chain and rear piston. Remove the threaded pin and chain guide roller at the front of the cylinder.

Using a suitable tool, push the rear piston to the rear and out of the cylinder. Then, using a plastic/wooden dowel rod of a suitable diameter through the hole which accommodates the cocking-lever-ball in the front of the cylinder, push the front piston and chain towards the rear and out of the cylinder.

The trigger unit is easy to work on and polishing of the bearing surfaces is easily done.
The rear piston engages with the trigger sear and this is rather more difficult to polish.
There are two adjusting grub screws, size1.5mm on the trigger. These are locked in place with another two grub screws size 1/16 AF.

Reassembly is the reverse of the above procedure. The plate and clip in the chain link fits better with a slight bit of tension on the chain.

I stripped mine down for a re lube (10 years old now) and to see what makes it tick. Provided all serviceable parts are in good nick, it can be put back together again without any problems.

I hope this is useful information for whoever is contemplating a stripdown of these airguns.


Cheers, Phil, with thanks to David, 'dvd'