If you can at all afford it, then skip the M3K and just buy a Benelli M2. I have at least 6 friends with the M3K, almost all have installed the Benelli extractor and about half of them can not get their gun to cycle consistently. It has something to do with the bolt not rotating enough when feeding a fresh shell. Buy one, cry once.
I have an M3K and don't have any problem with cycling. I did put a Benelli reduced power hammer and trigger spring kit from Taran Tactical and a polished aluminum follower in it. But it runs any load I put in it just fine. Of course if you can afford an M2 by all means get one