OK....I just received 100 rounds of 5.56 M855 green tip steel core penetrators. Went to the only area around here where there is a flat 100 meters/100yards+1foot range. Its not really a range, more like a gravel pit but sufficed regardless. I did ok but feel like i could've done better, but that's because I'm a little rusty and didn't think about not blinking, squeeze and hold trigger, sight in windege and elevation one at a time, tap adjustment screws after recapping....stuff like that. But anyway, was wondering if the ACOG TA31RCOM4 does better with 62gr or 55gr? Also, the Trijicon web site says it's calibrated for .223. Will 5.56 work just the same? The ACOG I'm using(TA31RCOM4) is designed for 14.5" barrels, mine is 16" 1/7 twist. Will using .223 work better or should i stick with 5.56 which is what I'm running and chambered in. I also heard that zeroing at 33 meters using the 300 meter stadia, will zero 100 meters...or something like that. Will the BDC be affected in this form of sighting? sorry if this is confusing. I just need help here in making sure my set up is correct and function correctly. Thanks again for all and any input.