Not all weapons are cumbersome – some can be brought to bear in less than a heartbeat, and let fly shortly after.
Quick to Fire
Quick to Fire weapons do not suffer the usual -1 To Hit penalty for moving and shooting. In addition, Quick to Fire weapons can always be used to Stand and Shoot against a charging enemy, even if that enemy would normally be too close for such a charge reaction to be declared.
Furthermore, Quick to Fire weapons may be used once per turn when declaring a charge (unless they are also Move or Fire), immediately after the enemy unit has declared their charge reaction (but before moving any units). If the enemy unit chose to Stand & Shoot or Fire & Flee, both units will fire at the same time. Quick to Fire weapons can be used this way even if the unit starts its charge outside their weapons' maximum range – the shooting is resolved normally assuming the enemy is just within maximum range of the shooting unit's shortest-ranged weapon. If the charge fails, for whatever reason, we assume that the chargers closed to within the weapons' maximum range first. Any shots fired in this manner suffer a -1 To Hit penalty.