I have owned up to 40 SKS at the same time over the years. To compare guns with the same brand of ammo, you MUST be positive that you use the same lot#.
I have used 1000 round cases of Wolf, Wolf MC, the original MFS 126gr Military, and Yugo M67.
First off, at 300 yards the para accuracy dropped off rather dramatically for me. Did not run it for these tests.
For testing I used a Yugo M59, Yugo M59/66A1, Romanian, Russian, and Chinese. They finished in this order. 20 rounds of each ammo listed above over an * hour time to let guns cool evenly each.
1. Yugo M59
2. Romanian
3. Russian, Chinese, and the Yugo M59/66A1 were tied at third.
I just repeated the test again 2 years ago. Same exact results.
Accuracy by Ammo, both tests.
1. Yugo M67 and MFS Military tied.
2. Wolf MC
3. Wolf (Black Box)