I thought this was going to be fun to shoot all these different calibers and ammo through 9” barrels but I was wrong. I went out on the MLK holiday when the range opened hoping to get done before the crowd showed up. Turns out most of the crowd had the same idea. What should have taken 3 hours tops took 6 due to the crowding at the range. It was also unseasonably warm and I forgot my water bottle so by the time I got home I had a killer headache. I blame part of it on firing more than 1K rounds of 3 different calibers through 9” barrels for 6 hours.
On to the data. I tried to be as “scientific” as I could be. I will admit that I am not a benchrest shooter. I was using a Burris 2x7 for all the accuracy testing. I don’t have a fancy rest or anything, I mounted my Bobro Bi-pod on the front of the gun and used a small shooting bag under the back to try and be as stable as possible.
Overall, I was fairly impressed with the results, especially the 85gr 6.8SPC. It was surprisingly accurate and carried itself at a good velocity.
Of note, I fired for function checks both before and after all the official testing. Everything ran fine, the brass cased surplus 7.62x39 had a weaker ejection than any of the other 7.62x39. I think that is probably due to the brass expanding after firing. The gun may need a slightly larger gas dial as I had to shoot at Setting 4 when firing the Egyptian and Dubai stuff. All of the rest of the stuff ran fine.
I had feeding issues related to the 7.62x39 magazines when I loaded more than 20 rounds. When I loaded 19 rounds I experienced no problems but as soon as I loaded more than 20 the bolt failed to pick up the next round due to the spring not being strong enough. I experienced this on both of the C-products mags that I have.
Here is the Data, all groups were at 100yards and velocity was measured 15 feet from the muzzle. I also recorded groups at 50y using various 1x red dot optics and they were all slightly better than the 100y stuff. As the sun got brighter I experienced some red dot washout so the 50y groups weren't as good as they could have been but they were all respectable in my book.
I am sure that I am leaving something out right now but it is late. Please ask any questions that you can think of.
I shot 4 different loads in 5.56, 2 factory and 2 reloads. The reloads were a light plinking load and a load made to mimic M193.
5.56mm Velocity at 15' Energy(Ft.-Lbs.) Group Size in Inches
Smallest Largest Average
55gr Reduced Reload 2285 Avg ES=146/SD=37 637
2.70 4.00 3.35
Remington UMC 55gr 2416 Avg ES=108/SD=32 713
0.66 2.46 1.56
M193 Reloads 55gr 2475 Avg ES=68/SD=21 748
0.99 2.42 1.71
M193 Factory 2488 Avg ES=81/SD=31 756
1.57 2.27 1.92
6.8 SPC Velocity at 15' Energy(Ft.-Lbs.) Group Size in Inches
Smallest Largest Average
Hornady TAP 110gr 2150 Avg ES=37/SD=16 1129
0.69 1.95 1.32
SSA 90gr TNT 2510 Avg ES=73/SD=29 1259
1.22 1.24 1.23
SSA 85gr Barnes TSX 2528 Avg ES=76/SD=29 1206
0.56 1.60 1.08
7.62x39 Velocity at 15' Energy(Ft.-Lbs.) Group Size in Inches
Smallest Largest Average
Barnaul 123gr 2015 Avg ES=80/SD=25 1,109
2.65 4.55 3.60
Brown Bear 123gr 2073 Avg ES=56/SD=17 1,173
2.43 3.90 3.17
Dubai Brass Cased 124gr 2033 Avg ES=59/SD=18 1,129
3.60 5.35 4.48
Egyptian Brass Cased 124gr 2043 Avg ES=54/SD=16 1,140
2.03 3.70 2.87
Winchester White Box 123gr 1904 Avg ES=49/SD=16 990
2.30 4.22 3.26