Well, the barrel is now recrowned, and I tested it today to find it shoots exactly the same!
I tested at 35 yards indoor, and the rifle still shoots the same 'little fingernail' sized 5 shot groups with AA Field, Daystate FT and H&N Baracuda when single loaded, and the groups of the AA and Daystate open marginally when using the mags.
So, it looks like I might change over to Baracuda pellets, but I wanted the flat trajectory, so will have to up the power from 30ft/lb to 40ft/lb.