The Battle sight , would be a sight normally with the larger diameter aperture opening for quick target acquisition and usually a zero @ 300 yds, so by putting front blade on middle of a man the soldier would strike up or down generally on torso out to 350-400yds. This option usually applied when a Rifle had a separate aperture for this purpose, like the No4 and then the C-7, different from the smaller aperture for more precise work at know distances. If I recall our FN's that replaced the No4's, the battle sight was the same folding disc aperture but the larger opening with the 200yd zero was deemed the "Battle sight".
On my AR and when Canada first replaced the FN with the C-7, its the flip down L-shaped part of the rear sight aperture that is largest, that would make quick, though not as precise, target acquistion possible,. I'm not famaliar with its zero for certain on this Rifle, but I assume it would be 300yds, current with the usual setting for the smaller aperture at 300 on the 300/800 sight.
Lots of current C-7 shooters here, who would have used the C-7 service Rifle with A-2 sights will clarify if I'm wrong.

I don't know anything of was considered the Battle "sight range" on the SKS with its leaf rear.