The Atlanta Arms 77gr OTM 5.56 ammunition is possibly the best match ammo for your AR-15/SPR/DMR rifle. Now while I have tested many companies match 5.56/.223 ammunition, I have found the Atlanta Arms 77gr OTM 5.56 ammunition to be the all around top performer. I have tested Black Hills, Gorilla Ammunition, Asym, Hornady, Cor Bon, HPR, etc. But when it comes to adding in the cost versus the performance, the Atlanta Arms 77gr OTM 5.56 ammunition sits between Black Hills and Gorilla Ammunition in terms of accuracy and it beats both in price. So when you are talking a few tenths of an inch, I will usually go for the cheaper round. Atlanta Arms 77gr OTM 5.56 ammunition comes in at around .81 cents per round, which is mightily below Black Hills and Gorilla Ammunition which are above $1 a round. So lets talk specifics about this Atlanta Arms 77gr OTM 5.56 ammunition.
In terms of what my testing consists of, I shoot three round groups on a bench at 100 yards. I use the same 18″ match barreled SPR/DMR rifle build and USGI magazines. So the consistency is there when I test all my ammunition. This specific Atlanta Arms 77gr OTM 5.56 ammunition comes in 50 round boxes and I saw no cosmetic flaws prior to hitting the range. I have shot many, many groups with this ammuntion and have really found it to be a very consistent round. There are some metrics which I find to be the secret sauce in testing ammunition. The first is average, what is the average size of the groups. This is going to basically take all the numbers and give you what you can usually count on if you use said ammunition. The other metric is standard deviation. What this will tell us is what is the standard difference in each group. This is what really shows how accurate ammunition is in my opinion. If you have groups that are all over the place but get averaged due to a few killer groups, then that is not a true showing. But if you have 100 groups that are only a tenth of an inch different on average then you know you can count on that ammunition to be a consistent performer.
Now coming out of the barrel I have had consistent feel. After shooting many rounds you get a feel for your rifles and I have shot a good amount through my newly built SPR/DMR build and I know when it is running sexy. This backups the standard deviation number as you do not want to feel a difference between rounds or that will most likely mean they will be all over the place on target. I am not a precision shooter, so understand the ability of this ammunition is better than my results. I shoot off a pack with a sand sock, so I find my results to be very real world in terms of “battle” accuracy. But lets get to the numbers. I have averaged .89″ in terms of diameter of my three round groups at 100 yards. Each round of the few hundred I shot loaded into the chamber and extracted perfectly. I really believe the only competition for this ammunition specifically is the Black Hills 77gr OTM. Both are very close in my testing with the Black Hills having to date an average group diameter of .84″ in my testing.