The experimental gunsmith is obsessed with creating the ultimate firearm, and is willing to take risks to work the kinks out of her design.
An experimental gunsmith has the following class features:
At 1st level, an experimental gunsmith begins play with an experimental firearm. This acts as the gunslinger's gunsmith ability, but the firearm the experimental gunsmith begins with has one innovation (see below). Further, the experimental gunsmith is treated as having the Gunsmithing feat, but only in regard to his beginning firearm (or the construction of a replacement firearm of the same design, if the original is lost).
This ability otherwise works like the standard gunslinger's gunsmith and Gunsmithing abilities and replaces those abilities.
An experimental gunsmith starts play with one innovation she can make to her experimental firearms, selected from the list below. This innovation is a radical change to the typical design of a firearm, and comes with both additional benefits and noteworthy drawbacks. The experimental gunsmith can maintain only one experimental firearm modified with one or more innovations, as it requires constant adjustments and much of her time is spent maintaining the weapon. If the experimental gunsmith takes the Gunsmithing feat, she can create other firearms using a single innovation she knows (or add one innovation to an existing firearm), though such weapons become unreliable over time. The misfire value of such weapons increases by 1 for each week after its creation, although the experimental gunsmith can return the misfire rate to normal by spending 1 day maintaining the weapon and spending 50 gp in raw materials. For the purposes of crafting such firearms, each innovation is treated as the masterwork weapon quality (with a value of 300 gp).
At 5th level, and every four levels after that (9th, 13th, and 17th level), the experimental gunsmith learns one additional innovation from the list below. These represent constant and increasingly skilled tinkering with a single firearm in her possession, and when the experimental gunsmith gains an innovation, she may immediately apply it to her experimental firearm. Once an innovation has been selected, it cannot be changed.
This ability replaces gun training.
Expanded Capacity: The experimental gunsmith increases her firearm's capacity by one (generally by adding another barrel, depending on the weapon's design). She also increases its weight by 50%. Because of the complexity of increasing its capacity, her weapon is more prone to misfire, and its misfire value increases by 1 (this is in addition to any misfire increase if the weapon is made with the Gunsmithing feat).
Expanded Chamber: The experimental gunsmith's firearm has a much larger than normal chamber for black powder, allowing her to use 2 doses of powder with each shot. The weapon grants a +1 circumstance bonus on damage rolls. However, when the weapon misfires, it causes a flashburn. This is the same as the weapon exploding (dealing damage from a corner of the experimental gunsmith's square), except the weapon is not automatically destroyed. If a broken weapon misfires, it is destroyed as normal.
Grapple Launcher: The experimental gunsmith's firearm includes a special set of rails that allows her to slide a grappling hook over the barrel and fire it as a full-round action. The grappling hook anchors into anything she successfully hits with an attack roll, and the DC of the Strength check required to pull the grappling hook loose is equal to her attack roll to lodge it in place. A Disable Device check can remove it with a +5 bonus on the check, and a creature struck by the hook can escape it with a combat maneuver check or Escape Artist check with a +5 bonus on the check. The firearm is powerful enough to fire a hook trailing up to 100 feet of rope, but throws off the balance of the experimental gunsmith's firearm, reducing its range increment by 50%.
Recoilless: The experimental gunsmith's firearm includes a series of gears, springs, and pistons designed to reduce its recoil and thus improve accuracy. The range increment of the weapon increases by 10 feet. However, the system is fragile, and easily damaged. Anytime the weapon misfires, this system becomes broken and does not function until the experimental gunsmith spends 1 hour repairing it.
Vial Launcher: The experimental gunsmith adds a special tube onto her firearm that can hold 1 vial of alchemical material, such as alchemist's fire, a tanglefoot bag, or a thunderstone. A special trigger allows her to channel the force of black powder into this tube to launch the vial as a ranged attack with half the range increment of her firearm. The experimental gunsmith can take this action in place of any single ranged attack, and may use the same attack bonus that she can apply to the firearm. If the alchemical substance has a save DC, it becomes 10 + 1/2 her experimental gunsmith level + her Wisdom modifier when she launches the vial from her firearm. This increase only applies to the initial saving throw. If additional saving throws are called for, they are resolved as normal. Reloading the tube is a time-consuming process and requires two full-round actions. If the weapon misfires while loaded with an alchemical substance, it detonates with the experimental gunsmith (and the firearm) as the target.