Lol, I have indeed had the same probs with my scar, but that was due to replacing the hammer with the ra tech hammer, wich is actually for an M4
after repairing and replacing it back with my stock hammer, the problems of my scar seem over.
and I always use a shitload of silicon oil for my trigger assembly
so I think and hope are due to the fact I havent fired the gun a lot yet, it might have to break in still....
when I shot it yesterday I only shoot 2-3 mags, so I will try again to shoot tomorow (today I spent all day with my scar and fixing it)