It's just not enough, not when ships are weaving about all over the place and you're trying to aim at a tiny lead indicator.

Alternatively, limit shots to two seconds apart in order to be able to let one off every time you press the fire button.

You must be using linked fire. This makes all guns fire at once instead of cycling through the weapons. It does a great deal more damage when it hits since more shots are landing at once, but it does burn through your energy quickly.

The lead indicator is tiny, but there's actually quite a bit of give here too. If you're even near the lead indicator, fire away. Chances are you're going to land hits. The closer you are to the target, the more this is true.

Have to disagree, here have an example of me more or less constantly firing. Well, at least when enemy ships are in range, no cutscenes are running, etc ;-)

https://youtu.be/QzCDfGraSh0