Thanks for the info guys. In the dreamline lite case there is no loctite in the hammer adjuster. It's definitely aluminium bits in there. The hammer, spring and adjuster are factory standard. The rifle has had a huma TP installed and 2 power plenums. The limit of the adjustment is dictated by screwing in the little grub screw until there is barely any free play in the hammer when the power wheel is on max. If you screw it in any further the power wheel can not be turned (without potentially damaging it) - on this rifle, this equates to balancing the hammer with a pressure of about 130 bar. (the manual says 160bar is the max)
I don't think there are any metal shavings coming from the valve, given their location mostly near the hst adjuster and very few at the valve end of the hammer.
My best guess at this point is that, as FX's run with no preload on the spring, the back end of the spring will travel forward due the overall forward momentum of the spring. The back end of the spring is quite sharp and could easily damage the aluminium as it slides by forwards and back. So I have de-burred and polished the spring ends/edges in the hope this will mitigate the problem.
