BCA Upper accept other BCG?

[grayfox]

I haven't looked at these for a while but there seem to be 2 types of side chargers, ones with the handle bolted into the carrier thru the eject port and those that have a left-side handle connecting to the cam pin. Any bcg that mimics the bca style should work. In the case of those with the left-side style you usually only need a special cam pin for it to work with any other bcg assembly.