According to military specs a 5.56 mm Nato load should have a 62 grain bullet and have a muzzle velocity of 3100 fps.
Now the bullet-Speer makes a 62 grain FMJ that is very close to mil specs, if anybody knows of something closer please speak up.
The big problem of mine, I don't know the powder to use and amout to get 3100fps from a standard 20" Nato 1in7" twist AR-15 barrel. I would like to very closely match the mil spec load but if a cleaner powder is suggested I will give it a try, but very important is the match to the 3100fps velocity to match the iron sight adjustments. Thanks