The secondary guns are more effective for long-range engagements due to their higher shell velocity and better penetration. However, the main gun is better suited for close-quarters combat because its HE or APHEBC shells can destroy most lightly armored vehicles.

Angle the SU-122 so its right-front hull edge faces the enemy. This hides the weak spot (the gunner’s optics) and reduces the chance of frontal penetrations when advancing towards small–medium targets.