Basic Firearms Rules
A firearm’s capacity is the number of shots it can hold at one time. When making a full-attack action, you may fire a firearm as many times in a round as you have attacks, up to this limit, unless you can reload the weapon as a swift or free action while making a full-attack action.
Loading a Firearm
You need at least one hand free to load one-handed and two-handed firearms. In the case of two-handed firearms, you hold the weapon in one hand and load it with the other—you only need to hold it in two hands to aim and shoot the firearm.
Firearms have a maximum range of 10 range increments.
Many modern firearms have a powerful kick after being shot. This can interfere with your aim. If a firearm has a damage bonus that is greater than your strength bonus, you subtract the difference from your attack roll.
If a firearm has a tripod, you subtract reduce this penalty by 1 in the attack modifier.
If a firearm is mounted, you subtract reduce this penalty by 2 in the attack modifier.
Firearm Rate of Fire
A firearm has at least one of the following rates of fire. A character trying to shoot a firearm set to anything other than single shot takes a -4 non-proficiency penalty to attack rolls unless she possesses the Martial Weapon Proficiency (Firearms) feat.
A semi-auto weapon can be fired like a normal ranged weapon. However, the user can take a full-attack action to fire twice, as if using the Rapid Shot feat (including taking a -2 penalty on all attacks). If the wielder has the Rapid Shot feat, she can use the additional shot from that as well, but the penalty for all shots fired in that round increases to -6.
A burst fire weapon can, as a standard action, fire multiple rounds. Make a CMB check against your opponent’s CMD. On a successful check, you hit the target. For every 5 your CMB check exceeds the target’s CMD, the target is hit by an additional attack. Burst fire requires you expend multiple rounds of ammunition per burst, as noted in the weapon’s entry. You cannot hit the target with more attacks than rounds fired. You cannot deal precision damage with a burst fire attack.
Note: Burst fire attacks take a -4 penalty to the attack roll at the Simple proficiency level.
An automatic weapon can, as a standard action, fire against all targets in a line. This line starts from any corner of the wielder’s space and extends to the limit of the weapon’s range or until it strikes a barrier it cannot penetrate.
When using an automatic weapon to attack all creatures in the line, the wielder makes a single attack roll, which is then compared to the Defense of each target in the line, subtracting 2 from the roll for every target hit. Creatures in the line take damage only once despite the hail of bullets, and critical hits must be confirmed for each target separately. Sneak attack damage is also only applied once per burst regardless of how many bullets realistically hit the target.
Effects that grant concealment, such as fog or smoke, do not affect an automatic weapon’s line attack. Roll to confirm each attack roll that threatens a critical hit separately. A single burst with an automatic weapon consumes 10 shots. When taking a full-attack action with an automatic weapon, the wielder can fire as many bursts in a round as he has attacks, provided he has enough charges to make all of the attacks.
Note: Automatic attacks take a -4 penalty to the attack roll at the Simple and Martial proficiency levels.
An automatic weapon can also be used to supress all targets in a cone. If used to attack all targets in a cone, it is treated as an AoE attack with a DC equal to the user’s attack roll – 6 (regardless of proficiency). Damage dealt to anything in the supressed area is rolled separately. Targets in the area are allowed a 5-foot step as an immediate action before the rolling of their save. Hint: Use it to jump behind nearby cover!
A broken firearm misses on a natural roll of 5 or lower instead of a natural 1.