I also did some groups at 100 yards using my KAC SR15 Mod 1 that has a Razor 1-6 on it. Again, temperature was around 38 to 40 degrees Fahrenheit. I zeroed this rifle using the MEN 56gr 5.56.
Attachment 54279
American Eagle 75gr TMJ
Attachment 54280
Speer 75gr Gold Dot (4 rounds are showing, I think I threw one high right off the target)
Attachment 54281
Asym 77gr OTM
Attachment 54282
CBC 62gr (my rifles across the board do not like this round)
I also did some comparisons with Asym 55gr 223 reman, AE 55gr 223, and MEN 56gr 5.56. My rifle really likes the Asym 55gr and equally dislikes the AE 55gr.