Your ammo test. It showed Barnaul made Silver Bear "Match" as being less accurate than Barnaul made "Barnaul" FMJ.
Granted there are a lot of variables to consider that can account for the few tenths difference, but Silver Bear Match, from your tests, wasn't as consistent as the equivalent Barnaul FMJ.
In any case, I read on AK47.Net that the "Bear" ammo isn't all made by Barnaul. There are other factories that produce the Bear series (Golden, Brown, Silver, Purple, Teal, Torquise, Fuschia, etc... :D )
You can probably ask Devil Dog or YODA from AK47.Net
And the other sure-fire way to tell is by using a Chronograph and testing accuracy. Barnaul tends to use a hotter charge, chronographing approx 2400+ fps muzzle velocities (7.62x39). Compare notes with data from other Russian import ammo and you can have some very useful data to tell which Bear ammo made by whichever company is the most desirable.