Idiots guide to classic airgun strips (pt 1)

[ggggr]

From her on its the same. The cadet and Major actually have the same trigger lever. Knock out the trigger pin and remove trigger, its spring and the little spring guide that looks like half a nail. You now need to unscrew the trigger block and may need a vice if the gun has not been apart for many years (or ever). On one I did I used the vice to hold the cylinder and placed a piece of thick flat bar in the trigger housing slot and levered it. (this was after plus gas and heat). This was why we removed the trigger--to allow this. Once undone,remove guide,mainspring and piston. Pison washer is leather held on by a special threaded nut. The piston rod used to be listed as a spare part but I dont know if it still is. Clean bits. See if trigger block will screw right home and slot line up with cocking slot. If not, Ive filed a touch off end of cylinder so you are not forcing thread on block. Lube and replace Piston, mainspring and guide and screw in trigger block. If you cant get proper mainspring then a meteor one cut to about 19.5 cm will do. Put guide pin in spring and locate and refit trigger and pin. On major refit sear and spring. Locate cylinder plunger and spring,refit barrel and then cocking arm. Replace action in stock and tighten stock screws. NEXT UP THE METEOR!



Just adding this that Ray (Abellringer) put up to help clarify things about the stock screws.



"Also posted in general airgun. This is in reply to a request to post an accurate thread size for the Front Stock Screws on both of these models. All of them are very similar and in fact will fit. It's worth noting there are two variations of screw; one has a reduced dia shank from the end of the thread to under the screw head; the other has the major dia all the way along to under the head. So starting with the correct one.

1] 7/32" BSF 55deg angle inc. 28tpi 0.219" O/D tapping drill 4.6mm

2] No 12 [7/32"] UNF 60deg angle inc. 28tpi 0.216" O/D tapping drill 4.7mm

3] 1BA 47.5deg angle inc. 28.25tpi 0.210" O/D tapping drill 4.5mm
Hope this helps in some way. "

[ggggr]

I think this applies to the Meteor mk3 version as well. The mk4 and mk5 versions mainly differ in that the mk4 has the single piece cocking arm and the longer slot in the stock and the mk5 has the articulated lever and the shorter slot. Sights differed a bit as well. Most pistons have the "keyhole" slot piston that the piston head slots into although some mk5,s Ive seen have the circlip set up like the scorpion. The front stock screws and the rear one are all 2BA thread. Later front screws are longerand will need cutting down or packing if used on an earlier gun. If you dont mind cheeseheaded screws, these can be bought for about 10p each from Chronos or the like. The earlier triggers had a wide metal trigger and sear. The later ones had narrower triggers and sears and the trigger became a slip on plastic thing you pinned onto the actual trigger piece. Ive seen sears with the large pivot hole round and others that are elongated. I think they all swap. Im noy sure if trigger pin sizes changed slightly at some point as I remember having to file some to fit the TE (mk3)version I had as a kid. The later versions have the trigger stop pin fitted so you only have to sort the other two. GO TO NEXT POST

[ggggr]

The pin for the cocking arm is different for the two versions and I fitted a roll pin when I was playing with one recently.
Remove sights and remove the 2 screws at the forend of stock and the trigger guard one. Carefully lift action from stock as trigger pins can fall out. Remove bottom pin and trigger should drop a bit. Remove top larger sear pivot pin and the trigger,trigger spring (bent wire thing) and the sear should come out together. On earlier version the trigger stop pin will also come out. REmove plastic end cap. Knock out cocking arm pin and remove cocking arm. (note piece of plastic In cocking arm on early version to stop pin moving). Break barrel and push in barrel plunger and knock out barrel pivot pin. Remove plunger and spring and then the barrel from the jaws. Place cylinder jaws down on piece of wood and using your bit of tube (SEE 1ST POST PG1) push down on guide and remove cylinder pin. Ease pressure and remove guide, spring and piston. The piston head may be loose if the piston buffer washer has rotted and crumbled (they all do). On the late version the retainig circlip may have broken and the piston will come out and leave the head behind! GO TO NEXT POST

[ggggr]

I used a foot pump with a bit of wet rag to seal the adapter and put it in the transfer post and managed to blow the head back far enough to wangle it with a dowel. (same trick worked on scorpion). Piston washer is an "o" ring. I replaced a buffer washer with two bits of leather (not worth the hassle but I was curious) and have used a tap washer in the past.Clean and lube. Slide piston buffre and its washer onto piston head and insert into keyhole of piston and it should snap into place although you may have to file small chamfer on one side of washer. With circlip set up a piece of tube to push clip on would help but Ive done it wirh two small screwdrivers. Place piston, spring and guide in cylinder and push down with your piece of tube and refit pin. It is worthwhile changing breech washer as it is made of same stuuf as piston buffer. I make leather ones. Place brech in jaws and fit plunger and spring,depress and fit barrel pivot pin. Fit trigger stop pin (tape on left side of trigger housing stops them falling out) then offer trigger,spring and sear into housing. Locate sear and fit pin and then trigger should push up to enable trigger pin to be fitted. Replace plastic cap and refit in stock and fasten screws. ( if you adjust trigger at all, 1/2 turn of the little screw in plastic in the trigger can stop the sear from engaging).

[Garvin]

Some parts diagrams:

BSA Airsporter Mk6
BSA Mercury Mk3
BSA Airsporter S
BSA Meteor MK5
BSA Meteor Super Mk5
Diana G79-G80
Webley Hawk Mk3
Webley Osprey
Webley Vulcan
Webley Hurricane
Webley Tempest
Webley Typhoon

[red bob]

probably one of the most imformative posts in years ,did a little job for guy; make up a couple of end caps for his zenit pistol ,the sort of thing i enjoy doing for the pleasure of helping a mate get a classic back to life in return he sends me the best part of a pistol for myself after admiring his example plus he gives me all the drawings and instructions to make up my own!
what he knocks up in his flat in manchester puts my efforts in a fully equiped state of the art factory in the shade,tapped my paratrooper trigger block back square over a block with a bar on his kitchen floor!.but his advise on knocking out the old pins and replacing the sear etc revived the above to full working order.ironic thing was our contact started with me advising guy on the pitfalls of refurbing the para[lol very loudly]cheers guy keep it up .

[ggggr]

This was an early Mercury but probably applies to others apart from the "s" which has a different breech set up and maybe more. Later ones have the articulated cocking arm similar to mk5 Meteors. Im hoping someone will put up the Bsa sheets that came with the guns to aid the thread.
Remove sights. Remove two front stock screws and large bolt that goes through pistol grip into trigger block. Remove action from stock. Remove cocking arm pin and cocking arm. Break barrel and depress barrel plunger and remove barrel pivot pin. Remove barrel,plunger and plunger spring (as always, looking outfor flying plunger!). Now you have to unscrew the trigger block. The one I did came out easily but you have a choice of oil filter straps, carefully gripping cylinder in vice and sliding a bar through that big hole in the trigger block and hitting it with a mallet. Some people have used heat and pipe freezing sprays. As alloy would contract more when cold I suppose you could always put the cylinder in the freezer for a few hours (I HAVE NOT TRIED THIS YET!). Once the block is loose unscrew it and carefully remove. Then remove guide, mainspring and piston. GO TO NEXT POST.

[ggggr]

The piston head is held onto the rod sticking out of the top of the piston by a small pin. Remove this pin and the head and buffer washer (or its remains) should come off. The seal is an "o" ring. Im not sure if some of the Mercury,s had a plastic head like some Airsporters, which spreads and goes tight in the cylinder and requires sanding down. T20 (Mick) told me he has omitted the buffer washer and cut its thickness off the rod at the top of the piston and then redrilled the pin hole BUT ADVISES the increse in swept volume could push the gun over the limit. The old washer will be knackered and need replacing if you dont do this mod. Clean and lube. Place buffer on piston head and head on piston rod and replace the pin that holds it.See if trigger block screw up ok and if not, adjust the big nut in the trigger housing till it lines up just right and then remove again.Replace mainspring and guide and screw home trigger block (I put breech down on piece of cardboard on a piece of wood to enable both hands to be used in turning). Change breech seal. Place barrel in breech jaws, replace plunger and spring and push barrel pivot pin through. Replace cocking arm and pin. Fit action in stock. tighten screws and then replace the sights.


I recently put one together that would not cock. It turned out that someone had fitted a bigger washer on the guide so it sat on the thread bit of the trigger block and not in it. I've been told the correct OD is 23.8mm

[ggggr]

This is only a rough guide as it covers so many. The mk2 had the automatic opening loading tap activated by a pin on the sliding cocking plate pushing on a plate screwed to the RHS of the tap. The mk2 and 3 also had a conical piston head and a leather piston washer. Some of these heads are fixed and some unscrew by using a special long tool that goes down the inside of the piston. Chambers will do the job for you if you buy the washer. The option I went for was the "retro fit" conical adapter that takes the later "o" ring. You fit this (after removing old leather washer) by throwing in cup of hot water and pushing over head of piston. As mentioned in the Mercury thread above, some heads were plastic and go tight and need sanding to fit. The trigger set ups changed and fitting the trigger spring on the mk 2/3 which uses a spring similar(but larger) to the meteor is a bit of a chinese puzzle.
Once you get all the cocking linkage off the gun, the strip is the same as the Mercury above.
Remove sights and then stock screws. The mk2/3 has one at the front that goes right through, later ones have two small ones. All have the large stock bolt through the pistol grip. GO TO NEXT POST.

[ggggr]

With action removed from stock remove cocking arm pivot pin from trigger block and lift arm clear of block. You can remove block and change mainspring but if the spring needs changing then the piston buffer washer will need doing on the later guns---SO. Remove pins from the small cocking arm link and the sliding plate. On some of the guns you will also have to remove the nut from the bolt (or the bolt) that holds the little support bracket and goes through the sliding plate. Remove the sliding plate and follow the Mercury guide for the strip down and replacing of the internals. Once you have done that it is just a matter of refitting the cocking arm set up, sliding plate,bracket and nut/bolt, cocking arm link and cocking lever.
Loading taps are different. The early ones had the lever as a part of them and the little spring and ball under the plate on the RHS (I think)---Later ones had a metal lever screwed on and the ball and spring in the tap at a right angle. It also had shims under the metal lever. Just watch and take care. If the gun does not fire a pellet out after you have done the strip the tap may be out of line and need a shim (on later ones) or the lever touching with a file on the inside face if catching on cylinder with earlier ones. Replace action in stock, tighten screws and refit sights.

[Gareth W-B]

This is a truly wonderful thread and sets the collectors apart from all others imo, as the spirit of help and support in this section is imo otherwise unrivalled here on the BBS. So to ggggr, many thanks from all in collectors corner . And if anyone else feels like contributing by posting links or scans etc, as Garvin has done, please feel free to do so -- the more the merrier . Atvb all: G.

[ggggr]

Im getting ready to do the Bsa Scorpion pistol next---but in the meantime, I posted on 31/5/2009 "some help with common problems" which hopefully will do as it says.

[ggggr]

There is very little difference between the mk1 and mk2 pistols other than the sights and the safety catch button going from steel with a plastic button to all plastic (less likely to break in my opinion). Im going for the full strip here rather than mainspring change. Ive had various threads on here requesting help in the last year or so and my thread "scorpion trigger help---again" may be of use or amuse you. We will assume your pistol is working to start off with.
Remove cocking aid and sights. With a very small screwdriver feel for the catch on the cap at the bottom of the grip and remove the cap (DONT FORCE IT OFF). Undo the stock screw at very rear of the grip. Use an allen key (3mm I think) to undo screw in the grip body (look down where you removed end cap.Un do safety catch screw and remove catch. Lift action out of body. The roll pins on the scorpion should have little plactic end caps which will need removing but these are often missing. Any loose roll pins can be opened up slightly when they are out by tapping a small screwdriver or similar into the slots to open them. GO TO NEXT POST

[ggggr]

Remove the 4 screws holding the trigger housing (keeping weight on it as long sear will push it up, unless you want to remove it and its spring) and remove the housing. DONT PLAY WITH IT OR THE SAFETY SPRING WILL FLY AND THEY ARE £5 A POP AT NIBBS . The cocking arms should come out of the slot now. Id remove the barrel pivot pin and remove the barrel now and while its off change the breech washer and remove the plunger pin to get at and lube them and all the pins. Place cylinder, jaws down on a piece of wood and use the forked tube (SEE 1ST POST ON THREAD) and push guide and spring down and remove cylinder end pin. Withdraw guide,spring and piston. Then piston head is secured by a small circlip ( about £5 at Nibbs!) on the inside of piston and I managed to remove with small screwdrivers. There was a flat washer over it which I assume is to let the spring push down to keep it in place. Remove buffer washer and "O" ring and clean and lube everything. Replace "O" ring and buffer and insert head into piston body. A piece of tube to push onto the circlip would be ideal but I managed with the screwdrivers again. DONT FORGET TO PUT THE FLAT WASHER IN PISTON! GO TO NEXT POST.

[ggggr]

Replace piston in cylinder,followed by mainspring and guide. Use the forked tube to push down on guide and replace cylinder end pin. (I think on the mk1 it has a recess that needs to be upper most). Replace your barrel and cocking arm. Before you replace the trigger, I found that you can squeeze a small washer in at the side of the small hammer spring (on the opposite side to the hammer spacer) and this helps square the spring up and helps it flick the hammer forwards when you fire the gun. The Bsa sheets said when replacing the trigger housing to remove the plastic sear guide and to slide the sear to the left, replace the screws and then the sear and guide. I used the method others have told me of cocking the trigger until it clicks (twice I think) and pushing the long sear up until it sits on the small sear in the trigger mechanism and pull trigger to click sear into place. Repalce the housing screws. Replace in body,refit safety catch and screw, the rear body screw and the one inside the grips and refit sights. If safety plays up you have to mess with the little R shaped spring and bend it but thats something else.

Well I did write something here and added a few pics and instructions but they went missing in the bbs update thing. Hopefully this like will work.
http://www.airgunbbs.com/showthread....Pistol-Trigger

Update--after asking for spring guide sizes for one that was missing --------total length 65mm----washer thickness 2mm--diameter or tube approxiamately 13.8mm (I used 14mm and it seems ok)


MAINSPRINGS ------------Ive had New/old stock springs that were 167mm long and found an earlier spring that was 192mm long. Ive been led to believe that some people have seen lengths of 177mm to 185mm. I tried a 167mm spring in a pistol and got under 5ftlb . With the longer spring power was over 5.8ftlb but the gun was hard to cock. If you buy a spring to cut down, Id go for easier cocking and power in the low 5ftlbs region


Update.
Scorpion trigger problems/ List

Ive had Scorpion triggers together maybe 40 times? I've probably done a dozen or so guns. Ive advised on a few of them as well. Here are a list of what I can think of of the various problems. I may update later.

(1) the little safety spring being out of plonk so the gun will cock but not fire. It throws the flat on the safety out so the front of the hammer will not pass through it when you pull the trigger. The Duff safety bar can do the same. You will get 1 "click" of the hammer going forward but it cannot go forward enough to hit the little sear with enough force. The little tang on the leg of the spring needs a small tweak.

(2) trigger adjuster screw wound out too far so when you knock the safety off the gun fires

(3) Bent or broken hammer --the long bit that the cocking arm pushes on. Usually caused by something else and force being used as the trigger bits are only like bits of Meccano

(4) a duff safetybar, where the gun would not fire with the screws tightened up in the grip.

(5) the long sear worn at the bit that holds the piston-------------the gun wont cock and hold, similar to if the holding face of the piston is worn. I had one gun that just would not cock and hold, and a new sear cured it, even though i could not see any difference between them. The sear would not work on another gun either

(6) the plastic guide having a bit sticking out and pushing the long sear to one side so the gun wouldnt cock and hold . Cleaned up the witness mark and worked fine.

(7) the little sear being bent and stopping the gun from cocking. Very difficult to spot unless you have one to compare it to. The long sear rests on it before the piston comes back far enough. Long stroking the gun can cause this.

(8) as above really. If you long stroke the gun then then long sear can contact with the little sear before the piston is far enough back. More force trying to cock will result in a bent little sear.
(9) I finally had this one------The spacer washer on the LHS of the hammer, needing a thin shim to stop the hammer dragging on the trigger housing. I think I used a bit of plastic milk bottle
I think that is it--BUT I have never had a problem with the little sear spring.

UPDATE -----another problem sort of cropped up. The barrel catch plunger didn't seem to want to break cleanly and as it broke it would just start to cock the gun, then the gun would not cock! The reason for this being, if the hammer is pushed back a little (and it pulls the little sear with it), the hammer spring will not spring it back into the starting position. This puts the little sear in the wrong position like in (8) above.
You may be lucky and if you pull the trigger with the gun pointing down it may go into place------But more likely, you will have to take the action out of the grip and push the hammer back into place with a little screwdriver.


On the subject of Plastic milk bottle shims, I have used them on one side of the adjustable foresight post to stop them wangling.


I have converted a couple of Scorpions to do away with the safety. There are a couple of ways to do it, depending on your skill levels and whether you want a totally original gun.


Today I improved the trigger buy replacing the spring that sits in the plastic trigger with a softer spring that I cut 3 coils shorter than standard. For me --it's pretty good, with a fairly light and short pull.