You know we had to delve into this eventually! I know we could write a book, but we wont. I just wanna sort it all out in a user friendly way, make some sense of a handful of things... Some things I've wondered getting into my AR; What is cannelure and what the heck does it do? What gr. bullet should i use through my barrel? What gr./type of bullet should I use for ----- ? and some related questions, like; Is it safe to use steel case ammo over the aluminum feed ramps? My knowledge is extreemly limited... I've only fired Hornady TAP FPD .223 55 gr. ballistic tip nickel plated case, Federal (Lake City) XM193 5.56 55 gr. FMJ, and American Eagle Tactical (Black and White box) .223 55 gr. FMJ. All three of these loads are right around 3200 FPS. We've done well with all three thus far and once the rifle was sighted in really well, the AE .223 55 gr. FMJ was shooting POA/POI at 80 yards through my 1:9 twist barrel. Theres a lot of ammo out there to sort through. Theres a lot of philosophy and myth it seems to me. I wanna understand these little bullets better myself, So, Lets get it on!!!