Are you using a standard AR buffer spring or a .308 spring? I have heard both schools of opinions on this, so I'd just like to know since your system appears to run fairly reliably.
Yes 9mm has probably saved more lives than any other cartridge because it is something people have on them all the time, but when you get into the AR platform 9mm just doesn’t stack up in terms of lethality. Just curious what gun did your grandfather use in 9mm?