Just bought a "Q" seven inch barrel for a 300blk build I am doing. They have their own MLOK rails for sale, but I am unsure if they will fit a MEGA upper. I thought that I had read that their uppers were proprietary, but I could be wrong. Can anyone chime in on if they are or not? Also, if that is not an option for me to buy, what companies have hand guards for a 7 inch barrel?

Thanks in advance.