well I ended up replacing all 3 hammers, 2 ratech ones and my stock.
None of em made my scar work good.
Even when I used the stock, because I superglued the roller onto the hammer => bad idea, cause the bolt wont return...
So I tried to apply super glue very carefully on the retainer pin only so the roller can roll.
And
problem is solved.
However, with my 2 new magazines, I see that the hammer is catched by the sear in full auto.
So I have to return to semi, than to auto and than I can fire.
With my original mag I do not have this problem.
I find this strange since the magazine has nothing to do with the hammer-sear operation.
So who does that happen with new mags?