I'm no scientist but I have tried a few tests with different ammo at 600 yds and with different rifles too. Seems that all of my milsurps prefer one kind of ammo over the other, but on average my rankings from that day were (based on accuracy, consistent groups,and general smoke&smell):
1-hand loaded match ammo (russian factory 188 from spam can)
2-russian factory 188 surplus 7n1
3-factory 10 bulgarian silver tip
4-tula modern ammo
5-factory 188 surplus 147gr
6-albanian surplus
I fired 5 rounds of each from my PSL, SVT-40 sniper, Vepr w/23" barrel, Finn m39 SOV, and a Remington m-91. Newer rifles generally shot tighter groups than the older ones, and i had to let the psl and svt-40 cool down between tests because their accuracy varies greatly when the barrel gets hot. The tightest groups that day were while using my Vepr with 7n1 ammo
1-hand loaded match ammo (russian factory 188 from spam can)
2-russian factory 188 surplus 7n1
3-factory 10 bulgarian silver tip
4-tula modern ammo
5-factory 188 surplus 147gr
6-albanian surplus
I fired 5 rounds of each from my PSL, SVT-40 sniper, Vepr w/23" barrel, Finn m39 SOV, and a Remington m-91. Newer rifles generally shot tighter groups than the older ones, and i had to let the psl and svt-40 cool down between tests because their accuracy varies greatly when the barrel gets hot. The tightest groups that day were while using my Vepr with 7n1 ammo