Looking to build my first PCC, trying to get a rough parts list put together but have come across a dilemma as to whether I want to run a designated 9mm (Glock) lower or use a standard 5.56 lower and run an endomag setup which imo looks better and I can reuse my pmags I have from my 5.56 that has since traded hands to a friend of mine, does anyone have experience using the pmag setup? How reliably do they run and is there anymore fine tuning or gunsmithing involved with this setup as opposed to running a 9mm lower? Thanks in advance