Hammerli AR20FT single reg conversion
Being a bit of a tinkerer I decided to try converting the reg from its standard double reg set up to a single reg set up as I only ever fill to 200 bar. But Im a little confused as to whats happening over the chrono. Initially from a full charge Im getting 780fps with AA 8.4s but as the cylinder pressure drops the velocity steadily drops as well to 750fps at around 100bar.
Any ideas why its doing that? I cant get my head around whats happening. Theres no creep so the piston is sealing ok but I guess the pressure at which it seals is changing, or am I on the wrong track there?
There does seem to be a slight leak from the cylinder to reg port as when the cylinder is removed after a few minutes the reg will dump its air but with the cylinder fitted its fine, no leaks. Would that cause it?
Any suggestions are appreciated, thanks.