New to the forum and wanted to share my tuning experience with my Crown Cont with the 700mm .22 barrel (no slug liner, though it's on it's way ;-)).
I use JSB Beast as the starting point to get the gun dialed in on as heavy of a pellet as possible and used the FX chrony to look for consistency. I increased the reg pressure to about 142Bar and then increased the hammer spring tension until my FPS started to stabilize.
It shoots the 33.9gr beast at about 812fps. Below a 5 shot record highlighted in the graph above
Then I moved on to the JSB exact 18.13gr and played only with the transfer port and the hammer spring wheel from this point forward, looking for good SDV and ES and FPS around 920-930
This is where I found my sweet spot...
My next effort is to work on harmonic tuning now to get a speed that gives me the most repeatable accuracy. But over a range of 150fps my ES stayed below 12 and SDV was on average around 3FPS.
When my slug liner shows up I want to repeat this and possibly increase the reg pressure to 150BAR, but hearing some comments here tells me that I may not get any extra speed out of the 33.9gr pellets without making some mod on the hammer spring. On a side note, I also got a tin of the H&N Piledriver (30gr) and they shoot pretty accurate out of the 700mm pellet barrel, going to be curious how they perform with the slug liner installed.