At this point in the battle, what can you do, but to continue firing? You've no other way to reach the giants, and truly, no certainty of safety even if you were to drag your muskets and sakers across to the barricades. You'll give no further orders - let the men continue to fire, and pray that the Splendour favors you this day.
Across the field, the battle carries on. Throughout your defense line, the men hurriedly reload their firelocks, filling the powder and ramming the pellet down the barrel before preparing the match for the firing yet again. Your enemies continue their charge, advancing towards the bridge as rapidly as their feet will take them.
It is, of course, not fast enough to outrun the bullets.
Your men deliver a volley yet again, an orchestral crackling of gunfire from across your sides accompanied by a puff of smoke. Yet even the smoke that flows into the air is enough to stop you from seeing the effect - hundreds of men across the enemy line dropping to the ground, struck down by the bullets thrown. It is a devastating volley - but stop them, it does not. If they had not expected such a great volume of fire, they do not show so. These mercenaries know full well that, close as they are, that escape shall prove no safer than the charge. They hope to find their escape through the front - through you! And so they continue on, arms at hand, stepping over those of their own that fall to the wayside, picking up pace as they approach the bridge.