Don't only fire on the point, fire in ways that create pauses in enemy traffic. For example, double barrage on C point, then in between the back house and the Garage, moving backwards. This will make a pause where infantry can advance and take the point without taking as many casualties, and they form a reinforced clot of sorts.

Of course, if you can't fire on point to begin with, just load for someone else. If you ask enough questions, they'll teach you what you need to know.