Someone correct me if I'm wrong but I have a Colt M4 that I won't run steel ammo through. As I understand it the expansion attributes of steel vs brass is what typically causes the malfunctions with extraction of spent shells. If that is the case, would there be a BCG that one could just pop in to deal with steel ammo?
Considering that steel ammo is well below the cost of brass cased ammo, it seems like a logical question.

