tried your suggestions today,without the mainspring,gun cocks,sets the safety,put some pressure on the piston,pulled the trigger,released the piston.so i shortend the mainspring again,reassembled,still the same what i did notice was when the sear clicked onto the piston it is fully engaged then when the barrel is returned it seems to pop out of the piston,so i put a stronger spring,to see if it would hold the sear in place...didn't work!!!!