Quote Originally Posted by philcbr View Post
Hi all
Can anyone shed any light on a problem I’m have with a BSA airsporter MK1/2 the piston will not latch with the trigger mechanism. It seems not to have enough travel while operating the cocking lever.
If I remove the piston from the cylinder and manually insert it into the trigger block it engages ok. I have noticed a previous owner has cut off some of the threads that screw in to the cylinder, presumably to allow the piston to travel further in to the trigger block. This method works fine on the bench but when the gun is reassembled the cocking mechanism does not provide enough travel to engage the trigger.
I don’t know if the gun worked before I took it apart as I didn’t check, but I can’t see how it would as I have only replaced worn parts.
Any help appreciated.


Phil
Take the mainspring out and try cocking the gun then. If it does not cock or only barely cocks, then it sounds like the piston is worn on the cocking slot and may need welding a little. You can try leaving the cocking lever off and move the piston back with a rod/ screw driver etc. If it engages with the trigger ok then the piston can move far enough back (doing it this way) and that would also sugget the cocking slot.
If the piston engages ok without the spring in, then it sounds like like the mainspring is too long and the gun is coilbound.