Idiots guide to classic airgun strips (pt 1)

[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.