The pistelle x68 is strong out of the box, very much more (~200) after big factory mods, which then additionally cause issues, such as unintended multiple shots fired and trigger jamming and needing pressure released to reset the trigger.
These issues specifically happened to this set-up pictured, AND NOT when using same setup, but turning off rear 88 gram co2 and only using 12 gram co2 located in the grip (note that it empties 12 grams in 3.25 shots !) Note additionally that I'm in sunny Orlando in higher heat index,... raising co2 pressures up to and beyond the pressure limits of the 12gr piercing cap.
I'm hoping for a 16" rifled & double threaded barrel to be available. I'll make do with 13" for now (coming soon). I believe I can add barrel lengths up to a total of ~18" & still have reserve psi volume to increase joules further yet !