Since it has a place for the MILSPEC bolt release lever, I kind of doubt it will take an upper with a LRBHO, but that is just me. AK does not have one and I don't hear people complaining about them. The Glock mag AR-9 that I have just doesn't have LRBHO. You fire the last round, or hear the trigger go click, drop the mag, insert another and pull the bolt back and release in one motion. I am a lefty, so it is no issue at all, just pull the charging handle back to my ear and release.