I should have measured the stroke... will do at next disassembly.
The gun is now shooting Geco 7grs at 660-670 with Maccaris 28mm seal on a steel dovetail. Still feels slammy.
All the seals and piston fronts I have fit in this gun so far have been marked by the end wall of the comp. chamber after only a little shooting, so it is clear that the port volume must go down.
The spring in this 7.5joule gun is quite soft, its a relatively thin wire (approx 2.5mm?) and has a coil diameter of about 13.5mm's.
Anyone know the dimensions of the springs they are using for the 10-11fpe setups?