How to use AT guns on the offense?

[FLG]

This is a tricky manouver but you can get your AT in position in front of a static enemy line. Generally I will move up some infantry. Fire on the defenders to try to use up their defensive fire and then move the AT in, remembering to select reserve movement to ensure it can switch to deployed mode in the same turn.

If you can't use up all the enemies defensive fire you will either have to accept the possibility of high losses from defensive fire, when you move the AT adjacent in travel mode, or save the AT for another day.