AR Accuracy

Even though my chronograph went dead yesterday I was still able to do some experimentation with the AR. Now I've been shooting that battle rifle as often as I can, but I've never checked it for accuracy. I assumed my misses were due to human error because it just has to be more accurate than my SKS and probably the CETME too. Right? The HoloSight is quick but not necessarily the most accurate sight around, so I mounted a 3-9 X 32 scope to check accuracy off the bench.



Here are the results of a 4 shot groups at 100 yards.



PPU 5.56X45 55gr M193 -> 3-5/8"

American Eagle (Federal) .223 55gr -> 4-3/4"

Remington .223 55gr -> 4-1/2"

Winchester 5.56mm 55gr -> 3-3/4"

American Eagle (Federal) >223 63gr -> 3"



Notice the best group size was 3". That's on par with my SKS using the cheapest ammo I can buy. I was expecting an AR to be about half that. I didn't have time to try changing the location of the flash hider. I'd expect that to have some effect since moving that weight will have an effect on the natural frequency of the barrel system. I'll try that next time.



The picture below shows the barrel with the flash hider removed. It's a little hard to see, but it's rough on the end, almost as if it was done on purpose. Sporting rifles are machined, and sometimes recessed where the bullet exits. The general wisdom is that doing this increases accuracy. Could it be that if it was cleaned up, I'd get better accuracy?



Before getting that done, I'll try moving the location of the flash hider. It's easier and less expensive. I think I'll try that before testing any hand loads. Besides, that will give me an excuse to do more shooting, as if I really require an excuse.