Mk3 trigger housing assembly
Hello, what is the procedure for fitting the sear, trigger and spring in the webley mk3 air rifle housing. My rifle was the last production model. I purchased it new in 1975.
Guy's strip instructions on the airgunBBS say:
Idiots guide to Webley mk 3 strip
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.
Hello Garvin, got the trigger assy. Working again. The problem now is when I use the cocking lever, it is setting the trigger but it is not locking the spring. I don't know if it is the sear or the shaft on the cylinder. Any ideas.
It sounds like the piston 'bent' (hook) is not engaging with the sear. Is the trigger spring definitely in? I'll ask Guy to chime in.
I'd take the mainspring out and also the piston.
Push the piston rod into the trigger housing and see what is happening.
If the sear engages with the piston rod/ the trigger holds the sear and then will release the piston rod when you pull the trigger, then that suggests you have the trigger assembled correctly.
If that is ok, replace the piston in the cylinder, but leave out the mainspring and guide and also the cocking arm.Screw the trigger block on. Slide the piston back with a screwdriver etc and see if it engages with the sear and trigger. If it does then replace the cocking arm and try cocking the gun.
If the gun cocks then it would suggest that when you replace the mainspring the spring is gettting colibound.
If it doesnt cock with the cocking arm but no mainspring, then you are either looking at the piston being worn at the bit the cocking arm pushes on ---Or the cocking arm being bent.
The first Mk3 I did, would not cock---------and i later found out the sear had broken but someone had cleaned it up--------so it wasnt obvious!
Hello, followed you steps, this is my findings------ when I hold the trigger assy. and insert the cylinder shaft the trigger is cocked and when I pull hard straight out on the cylinder, it is holding in the trigger assy. But while pulling the cylinder if I twist it a little to the right or left it just slides out. I don't know if this is normal. I also tried the piston alone and cocked the gun and the piston shaft went in and cocked the trigger. When I pulled the trigger it released the piston shaft but when I install the main spring and clock the gun it cocks the trigger but will not hold in the trigger assay. Only sets the trigger.
These things are easier to sort out by a phone call. if you can get on one of the forums, i'll give you my number.
Firstly, was the trigger engaging and holding before you stripped the gun?
If the gun were mine, I'd be looking at stripping the trigger again and holding the piston rod up to the sear and see if the faces mate well, like Garvin has mentioned.
However, for now , I'll assume you do not want to strip the trigger again.
Put the piston in the gun, with the mainspring but leaving the guide out. If the the gun cocks and holds then that would suggest that with the guide in, the spring is coilbound. Taking a coil off should sort it.
If the gun doesnt cock and hold. Id try to put a little bit of thick shim steel between the cocking arm and the piston. If the gun now cocks and holds, that would suggest that either the piston is worn where the cocking arm pushes or the arm is a little bent.
If the gun still does cock and hold, then you are back to trying the piston rod into the trigger block------and see if you can adjust the trigger (lock screw on the side---adjuster on top of the block).
If the gun has had any of the faults mentioned earlier (Big spring/ coil bound/cocking arm a little bent or wear on the slot in the piston), then that could have caused the sear and trigger to barely engage the piston rod and now the piston rod and sear are worn. I'll assume you have got the trigger spring in place and it is not crushed?
Some Mk3 sears were made of sintered steel-----and once they start to wear, they dont last too long. The same is true with some of the Webley pistols.
What does it mean when a spring is coil bound?
When the spring is fully compressed and still too long to let the piston travel as far as it needs to.
Hello, disassembled the trigger assy. again. When taking a close inspection of the sear, I noticed a small split running from the pin hole on one side to the other side. I put my nail in the split and the sear broke in half. I live in the Netherlands, I left the UK years ago but I can't find any dealers for mk3 air rifle parts over here. Do you know any companies in the UK where I can order mk3 parts.
Hello, have placed the order for the sear from proteksupplies. Just as a matter of interest, if replacing the sear and the piston rod is still not holding, is it difficult to remove the rod from the piston cylinder or is it safer to replace the complete piston with the rod already installed.