M855 is 62gr not 55gr. Did you get the weights backwards?
If I could get my hands on Federal American Eagle 62gr FMJ-BT without the penetrator I would by several cases.
Between M855 62gr and Fed American Eagle 55gr I would take which ever is cheapest if I was shooting paper. For matches where steel targets are used don’t shoot M855 of any other 62gr penetrator load.
I have had great results for the American Eagle 62gr. Very accurate and the 62gr FMJ works well will the multitude of sights calibrated for the M855 62gr military loads.
I am sure that it can’t be any worse or better than M193 or M855. I worry more about putting rounds in the right spot which generally solves the problem.
55 grain M193 Ball (FMJ) is my choice, for cost mostly but it is also an effective self defense round.
It will shoot accurately in any barrel twist of modern AR15s, including 1:12, 1:9, and 1:7.
55 grain FMJ will fragment reliably at 2700 fps or more, depending on barrel length that is out to 100m (approximately). By fragment, the I meant the bullet comes apart as it is spinning, almost exploding (but no, it is not an ‘exploding bullet’. But it can be very devestating. Good for self defense, within the range of house defense, very destructive to tissue.
The drawback (or additional plus) is that penetration is greatly reduced at the shorter ranges. When the bullet speed has dropped below fragmentation speed, it will stay together and provide more penetration when it impacts something (walls, obstacles, flesh). Damage is reduced accordingly.
I tried some of the AE 62gr in 2002. It is not the same as M-855. It’s loaded to .223 not 5.56. I got an average velocity of 2861fps out of a Colt 20in with a 1/7 twist. Compare that with the Winchester M-855 that I shot the same day with a velocity of 3010fps. Also the AE doesn’t have a steel tip. As a further comparison XM-193 got a velocity of 3168fps and Win Q3131A got 3105fps