well anybody with an agm type mp40 will know about the stock wobble isue,what ive set out to do is reduce this as mutch as possible in ways that anybody could do with nothing mutch more than hand tools and elbow grease(if you can find it ,if not regular grease will do).
there seem to be 3 arears in the stock that have been made with exessive amounts of clearence or "play" whitch cause wobble in 2 planes,firstly the stock can move up and down excessivley and secondly left to right.
im going to start with the left to right play as ive found a simple remidy already.this is caused by the left and right sides of the stock not fitting closely enough to the gun body,that is that they need to be squeesed together more.
right to fix this you will need a 2.5mm drill bit and an m3 tap for cutting a thread and finally an m3 grub screw 3mm long and the allen kek to adjust it and some thread locking compound or super glue.
firstly you need to knock out the pin that conects the stock to the thumb catch,it just taps out ,one end is knurled to give a tight kit (interfearence fit).
once the pin is out it will all sprong appart,remove the stock from the gun,now one arm of the stock has a shaft that goes through the back of the gun and into the thumb catch,this shaft has a hole in for the pin to go through.now what you need to do is drill a 2.5mm hole into the end of this shaft through into the hole for the pin,now tap a thread into this hole with the m3 tap.with that done screw the m3 grub screw into the hole so it's end is level with the hole for the pin.
this is what you should have,now re assemble just the stock and pin ont the gun without the spring or thumb catch, adjust the grub screw untill the two sides fit more snugly but without excessive friction,thread lock the grub screw and re-assemble with the spring and thumb catch and the left right wobble will be gone 
armoury
m1a1 Thompson,sten mk2,mp40,stg44,sterling,mk2 bren gun,lee Enfield no4 mk1,Mauser Kar98, Walther ppk,smith and Weston m10 and Mauser m712
Give me a big enough hammer and a place to stand and I could fix the world.
i'll kill a man in a fair fight or if i think he's going to start a fair fight or over a woman or.......
a problem shared is a problem halved ,but an advantage shared is no advantage at all
if a job's not worth doing then its certainly not worth doing well
the vertical wobble is caused by 2 arears around the thumb catch.
firstly there is too mutch movement between the stock and the thumb catch and thats where we'll begin.
for this you are going to halfords or to raid your grandads tool box for feeler guages.for those that dont know feeler guages are a set of thin strip's of hard steel of exact thicknesses used for measureing verry small gaps.most sets come with a rivet at one end holding them together like a fan ,firstly gou need to remove that rivet *(or screw ) so you are left with a set of then strips of metal about 7-8 cm long with a hole in one end.now you need to remove the pin holding the stock parts together and remove the stock .now place the thumb catch in place in the left arm of the stock in its normal place,now select two of the feeler guages of similar thickness that will fit one either side of the thumb catch between the stock arm and the catch in sutsch a way that the catch will still move freely but with mutch less play.with a pair of tin snips or your wifes best scisors snip of the end of your two selected feeler guages with the hole in ,see pic
finaly re assemble with the two bits of feeler guage in place,see pic
this wont stop the wobble but it is reduced greatly.
im still working on a way of reduceing the play between the thumb catch and the gun whitch is all thats left.
hope this helps.
armoury
m1a1 Thompson,sten mk2,mp40,stg44,sterling,mk2 bren gun,lee Enfield no4 mk1,Mauser Kar98, Walther ppk,smith and Weston m10 and Mauser m712
Give me a big enough hammer and a place to stand and I could fix the world.
i'll kill a man in a fair fight or if i think he's going to start a fair fight or over a woman or.......
a problem shared is a problem halved ,but an advantage shared is no advantage at all
if a job's not worth doing then its certainly not worth doing well
Brilliant... What an easy fix!!
Many people say just let it wobble.. But I cannot believe Teutnonic enginners, armourers and gunsmiths (not to mention my wife) would go along with that viewpoint.. But then again I'm not German..
Ps. can you remember roughly how many 1000's you used of the feelers.. Or is it suck it and see..
Regards
'Non adepto demens. Adepto etiam'
War does not show who is right, only who is left..
one was 0.08mm the other i cant find now but a similar thickness,you dont want it to tight otherwise the catch jams.it doesent seem mutch but removeing a little at the pivot removes a lot of movement at the butt.the best thickness will probably vary gun to gun a fair amount.
another thing ive done is worked super glue into all the sleeved joints on the tube parts of the arms as there's a lot of play in those to,just put a spot of super glue on the joint seam and flex the joint and the glue works itself in ,keep working it in till a few drops have gone in then wipe of the exess and leave it till dry.
none of this will iliminate the wobble but it does reduce it markedly and none of it's to hard or expensive.
armoury
m1a1 Thompson,sten mk2,mp40,stg44,sterling,mk2 bren gun,lee Enfield no4 mk1,Mauser Kar98, Walther ppk,smith and Weston m10 and Mauser m712
Give me a big enough hammer and a place to stand and I could fix the world.
i'll kill a man in a fair fight or if i think he's going to start a fair fight or over a woman or.......
a problem shared is a problem halved ,but an advantage shared is no advantage at all
if a job's not worth doing then its certainly not worth doing well
