The 75 Amax has a very long ogive so they aren't the best thing to shoot in a chamber with a long lead(throat) like the 5.56. The good thing is they are cheap so why not give it a try.
I have a 6.8 necked down to .224 with a short throat designed just for the 75 Amax and Berger and can get 1/4" groups so the bullets are good, just never tried them in 5.56 chamber.
The 75gr Hornady Match shoots great almost duplicate of a 77SMK.
Hi perf barrels and bolts
8 twist, 5R, Melonite, Wylde chamber