asi/gamo mc supermatch target rifle help please.

[wadcutter]

I understand exactly what you are saying about the way the piston and valve operate but I am still no wiser on how to fix it, it cocks and fires but almost no power but I have not stripped the piston to see whats in it,as far as I know it has to have some oil in it and a air gap but I could be wrong this thing is giving me brain ache,all I did initially was change the rotted seals for o rings that seemed to fit but the inner piston you can push in and you should not be able to so till I look inside the piston im still a bit stuck but im getting there.

[Helm]

hi all
gedfinn reread my post re trigger piston
the vibration i and 18 wheeler was referring too
is the oscilation of the barrell as the pellett travels up it
you should read sigge olofsson on this ..he designed it and the lgr for walther..

wadcutter
if you unscrew the back of the piston and fill with chemical metal or other two pack you can always nock it back out
personnally not had to touch mine for a year since i fixed it
check that it doesn't leak through the trigger piston as these will have perished replace large seal with two o rings and the other with a flat seal as i said i used the soft pkastic seal from a kitchen sink and made a punch
these will both need a spot of silicon oil also the breech o ring i would replace as its probably hard?...
cheers ian