Question on a condor shroud

If you put a 12″ barrel in one, how many inches of the frame shroud is left over to stuff baffling material into? I suppose you would need an end cap too if you bought one that had an 18 or 24″ barrel already huh?

Would this tone it down to the equivilent of an SS with 12″ barrel and baffling in the shroud and would the condor produce more stock fps with this setup as compared to a stock SS in .22 calibers?