Quick newbie questions...

[ComradeP]

The "new" Katyusha units (like in the patched version of Moscow '42) with a minimum range are certainly priority targets. The "old" ones are less powerful, often more annoying than truly deadly as long as they're 8 gun units.

Rocket units have a much shorter than guns and howitzers, so they have to be placed closer to the front and move along with it when it moves. This makes it more likely that they will be spotted by the counterbattery fire mechanic, particularly when they're fairly big (18 or more gun) units. Their limited range and having to move them also means that you're more likely to spot them moving around in T-mode, as Plain Ian wrote.

Taking a closer look at your screenshot, I'm guessing there must be some units off to the east that are within 10 hexes of the enemy artillery unit, as none of your units in the screenshot are in range I believe. Or maybe the Soviets bumped some unit of its hex after it spotted the artillery unit when it fired on the Soviet turn. I'm not sure when, exactly, the counterbattery fire mechanic is applied: during a turn or if it determines which unit were spotted when you hit end turn.

The counterbattery spotting mechanic range limit of 10 hexes is counted from unit to unit, if I interpret the rule correctly.