Milsurp is all over the map. It all depends on your rifle. No one can tell from one rifle to the next what ammo it will like best. I've heard and read countless testimonies about the merits of one milsurp vs. another, but the proof is shooting them out of yours. You'll have to try it to know for sure. I know you're looking for a suggestion on where to start, but it won't work that way.
For instance, Hirtenberger had a great reputation (when you could get it) for accuracy "better than the rest". Port and Radway Green were supposed to be very good, but just a notch below Hirtenberger. My Super Match M1A hated milsurp. H, Port, Radway, South African, it didn't matter. Oh sure, H shot "better" groups, but that was still NINE MOA at its' best. I'd miss the ram at the 500 M line, and couldn't stay on paper at 300yd (w/ NRA 200yd target). Port, Radway, and SA didn't group well enough for me to measure. Literally. I guesstimate 12"-16" at 100yd depending on the country (or lot).
On the other hand, FGM 175's shot .75-1.0 MOA, BH shot just about the same, and handloads shoot .4 MOA out of the same rifle. I took a friend out to the silhouette line, and fed him FGM. He missed one ram out of 30. Never shot a gun before, and knocked them down so routinely with good ammo he got bored; at first he thought it was fun. I fed him some Hirtenberger, and he couldn't stay on the pigs better than 70%. Now he's got the bug.