Interesting read, as I have one ready to fit (not the latest type) but resisted as my MPR is very good over the chrono with a good 60+ shots all within an acceptably close fps variation.
I do have a carbine 410 for hunting that I might fit it to though, and I am looking to see what different people have done to get the best out of theirs.
Did you drill a vent in the cylinder and remove the firing pot? Rob marked mine with two settings for me to play about with, a 90 bar and 100 bar setting.
Thanks for posting your findindgs.