Just a little follow up, having greased up the return and buffer springs, the nasty twangs have gone.
Took out the trigger box which was so ridiculously easy, cleared off the existing much and replaced that, I know have a lovely clean break, much better than the marui stock box.
Getting a good seal with guns modify PMAGs, fitment in the magwell is actually very nice, tighter than the stock mag, bumps up the fps a tad.
Next I will be replacing the nub with, keeping the standard bucking for now to see how she goes, in its current form lifting .3’s seems to be no issue (haven’t got anything heavier at the moment)
Has anybody done anything to theirs they’re happy with? Might try modding the catch on the charging handle as that occasionally flys back.