Help on destroying the Bruno Railway gun.

[Sneaksie]

This is a tough one Go crouched on right flank and infiltrate the enemy rear. Lure enemy 4-barreled AA gun away from the main force and immobilize it (shoot at its tracks with a PTRD). Kill bailed out crew and capture it. Then lure enemy vehicles to it and destroy them one by one.
In th end, place TNT underneath the gun to destroy it (its in the orange-labeled crates nearby).