The thing about gun mages and their unique combination of magic and firearms is that they are trained in only one place, here in Tanton at a school in the mages quarter. No one knows exactly who first thought to enchant a pistol or even who produced one of the expensive firearms first but there is no doubt who first used them in battle; His Royal Highness Erik Donovan, King of Tanton. At the time these weapons had been around for a couple of generations, cannon and pistols were a sight, if not a common one, on battlefields everywhere. Humans, orcs, gnomes even dwarves sometime use them, it was only the elves who still deigned to use the loud, smelly, inaccurate things in their warfare. But when the Black Sheet Corsairs, a group of pirates from the south, landed in Teon, one of Tanton's allied cities, one company of the Tantonian first supported by one four gun mages had been more than enough to drive them to the sea. But it is not just martial proficiency that Gun mages are known for, they are very hard to get into, any who wish to wield the magebound pistols that are their tool has to uphold the very highest standards of honor and protocol. They are expected to act honorably and be an example to others.
~Captian Thorton Gangees, Royal Military Historian~

Gun caster, Spell Slinger, Tempest Mage, by many names these strange fighters are known. But all have one thing in common, a strange arcane connection to their pistols.
Prerequisites:
Feats: Weapon Focus(Pistol), Point Blank Shot
Skills: craft (firearms)4 ranks
Must be able to cast first level arcane spells and know at least one evocation spell.

1	+0	0	2	2	Atunement, Gun Bond, Bonus feat	+1 Arcane Caster Progression
2	+1	0	3	2	Crack Shot +1	+1 Arcane Caster Progression
3	+2	1	3	3	Bonus Feat, Magic Bullet
4	+3	1	4	4	Crack Shot +2, Improved Gun Bond	+1 Arcane Caster Progression
5	+3	1	4	4	Bonus Feat
6	+4	2	5	5	Crack Shot +3	+1 Arcane Caster Progression
7	+5	2	5	5	Bonus Feat
8	+6	2	6	6	Crack Shot +4	+1 Arcane Caster Progression
9	+6	3	6	6	Bonus Feat
10	+7	3	7	7	Crack Shot +5, Arcane Flurry	+1 Arcane Caster Progression

Skill Points: 4 + Int modifier
Class skills (and the key ability for each skill) are Bluff, Concentration, Craft, Intimidate, Jump, Knowledge(arcana), Listen, Perform, Profession, Spellcraft, Spot, and Swim.

Arcane Attunement: The Gun caster may cast the following spells as spell like abilities a number of times per day equal to 6+charisma modifier. Arcane Mark, Dancing Lights, Daze, Detect Magic, Flare, Ghost Sound, Know Direction, Light, Magic Attack, Mage Hand, Mending, Message, Open/Close, Prestidigitation, Ray of Frost, Read Magic, Resistance.

Crack Shot: At second level the gun caster improves his aim and receives +1 to attack and damage with all pistols. This bonus goes up by +1 every even numbered level thereafter.

Gun Bond: the Gun Caster forms a bond with a pistol in his possession. The pistol must be magicly enhanced. The Gun Caster must reenforce the pistol with at least 200 GP worth of jewels and precious metals. He may only have a number of attuned pistols equal to 1/4 his character level. At first level, when casting any spell of first level or lower, the Gun Caster no longer needs arcane somatic or focus items to cast any ray, ranged touch or line attack as long as he has a pistol that has been in his possession for at least 24 hours, and the Gun Caster is able to hold the pistol. Although any component worth 100 GP or more must still be supplied by the caster. Also, when ever the Gun Caster castes a spell that has an origin emanating from the caster, the origin point is his gun barrel.
At second level the Gun Caster’s bonded gun can be imbued with a single spell that has an area effect. An imbued bullet may not also be a Magic Bullet(see below)
At third level the Gun Caster no longer uses verbal components when casting through his bonded gun.
At fifth level the Gun Caster may imbue a spell with the range of touch on his bonded gun.

Bonus Feat: At first level the Gun Caster may choose any of the following: any Metamagic feat, Combat Casting, Quick Reload, Dodge (Mobility), Improved Initiative, Presice Shot (Far Shot, Improved Precise Shot, Shot on the Run), Quick Draw, Spell Focus (Greater Spell Focus), Spell Penetration (Greater Spell Penetration), Weapon Specialization (pistol).
And at every odd numbered level he may choose again from this list.

Improved Gun Bond: At 4 level the Casters bond with his pistol strengthens and he can now see from the end of the barrel as if it were one of his eyes. This allows the caster to ‘see’ with the gun even if his eyes are shut or otherwise blocked. This gives the Gun Caster blindsight, sixty feet. (With blindsight one must still have line of effect to the object) also, the hardness of the weapon increases by ten and it gains an extra twenty hit points.

Magic Bullets: Stop laughing, they hurt. Starting at third level, the Gun Caster may ‘loose’ a prepared spell, or a daily spell use as a move action to infuse a single bullet with arcane energy. That bullet now does +1D6 damage per level of the spell lost. This is non aligned force magic damage. The spell must be no higher than one less than the highest level of spell the Gun Caster can cast, so if the Gun Caster can use fourth level spells, he may only infuse up to third level spells. This is a magical enhancement to the bullet and fades if the bullet is removed from the caster’s gun or twenty-four hours, whichever comes first. The Caster may only have a number of magic bullets in existence equal to one-half his character level, round down. Only masterworked quality bullets may be enchanted thus.( It is common for Gun Casters to make his own, each with his unique arcane mark engraved on it)
Seeker Bullet: At sixth level the Caster can form a number of seeking bullets. These bullets seek out week points in armor and flesh, even curving to find the proper opening. On a shot made with a seeker bullet the Gun Caster halves any cover bonus the target has as long as the Caster can see the target. This shot also has a critical threat range of 18-20 and is made with a +5 enhancement bonus to the attack roll. These bullets count towards the casters limit on Magic Bullets.
Phantom Bullet: At eighth level the Gun Caster now can make a single Phantom bullet per week. This bullet is made from a single piece of gold and ignores all cover bonuses, including full cover, all armor and natural armor, and all damage reduction. The target must be in range of the gun and the Gun Caster must be aware of the target. Only one of these bullets may be in the casters possession at a time. No one but the one who made the Phantom bullet may use it. Some jokingly call this a ‘golden BB’

Arcane Flurry: as a full round action the Gun Caster with at least two pistols in hand may make a single shot with his pistols at each target within sixty feet. Each shot is made at his full base attack bonus -2.

Definitely too easy to get. I'd bump up the craft requirement to at least 8, because currently you could get it at second level, I believe. A spellcasting-class human would have the feats, spells, and skills required. Maybe a BAB requirement too?

I made it that easy on purpose, all my homebrew prestige classes have low requirements.
I think the ones they have are far to restrictive. They recommend that prestige classes be unavailable until level 7+. But one of the reasons I like to play at that level is because I can take a prestige class.

Do you have stats for firearms, wondering because I was wondering if such a gun could be overpowered.

Firearms in the known lands are based primarily upon the flintlock design but there are exceptions to this rule. The most noted of which are the spring-hammer weapons favored in the city of Tanton. But then again, rare materials are, comparatively speaking, easer to find in Tanton.
The standard firearm is a reenforced steel tube in which is drilled a small hole. One loads the weapon my pouring a small amount of flashpowder down the barrel and ramming a lead sphere down behind it.
More powder is placed in a small ‘pan’ located near the hole where a small flint is kept suspended above it by a steel spring. By pulling the trigger of the device you dis-engage the spring causing the flint to spark across a rough surface directly into the pan igniting the powder there which in turn ignites the power in the barrel. It is his rapid expansion of the powder causes the lead sphere to be driven out at killing speeds. In only the method for igniting the powder in the barrel does the style of firearm really change.
For game play all firearms do ‘ballistic’ damage. This means that at point blank range (within five feet) the weapon ignores up to ten points of armor, shields and natural armor. Only armor gained through force magic (mage armor and shield spells) overrides this. So, for example, a magic suit of armor ignores this and provides normal protection.
Also, firearms are very devastating when they find a chink in armor so any critical hit scored with a firearm (not a cannon or mortar) is treated like the user has Power Critical feat (+4 to confirm critical hit).
Any who are subject to a hit critical from a firearm must make a Fortitude save Vs. The amount of damage taken or be stunned for two rounds.
All firearms have a critical threat range of 20 unless noted.
note: a cannon must confirm a critical on all of the targets hit.
One never adds strength or any stat except for intelligence , if one has a way, to firearm damage.
To reload a pistol takes a full round action preceded by a Craft(firearms) skill roll Vs. DC-10. So taking ten on reload rolls always succeed. So with that it takes a standard action followed by a full round to reload a pistol. Cannon are much the same except it take TWO full rounds to reload one.
A one rolled in combat for an attack roll means the gun has jammed, if a second roll is low this means the shot failed also. If a third low roll is made something very bad may happen. A jammed firearm takes 1D6 rounds to clean and a successful Craft(firearms) roll Vs. DC-10.
The feat Rapid Reload allows one to make the Craft check in the same round you reload the weapon.

1	Tanton army issue	2d6	40ft	300gp
2	Kaslan Pistol	2d8	20ft	350gp
3	Holdout Gun	2d4	20ft	275gp
4	Blade Gun	2d6	30ft	400gp
5	Pintucker Pull-Fire	2d6	60ft	465gp
6	Pintucker Twin-Shot	2d6/2d6	30ft	700gp

Tanton Army Pistol
Produced by Carson Gunworks, one of the first pistol manufactures, this light firearm is standard issue for most Tanton army troops that make it past Corporal. The weapon is about eight inches long and fires a 50 caliber lead bullet. Although this is a rather small bullet this gun is widely claimed as one of the best firearms made. The secret is the fine craftsmanship put into the gun, while being smaller than most readily available small arms and doing less perceived damage per shot, the weapon fires its projectile at a faster speed while being more accurate than most others, giving its users a decided advantage in combat.
This weapon always counts as master worked. This cost has been worked into the price.
Due to the extreme muzzle velocity of this gun, you may ignore the first three points of AC gained through armor, natural armor, or shields for shots made at no more than its full range increment.
This weapon threats a critical on 19-20.

Kaslan Pistol
This rather large heavy caliber pistol is used primarily by the armies of Kaslow and is rather uncommon in the south. Popular with a tough crowd because the oversized firearm looks heavy and deadly. Heavy as it and kicks harder, in fact this weapon is so heavy it can be used as a weapon in melee, I counts as a heavy club doing a D8 of damage. The other thing about this weapon people like is that it kicks like mule, any medium creature shot with one must make a fortitude save Vs. the damage taken or become shaken for two rounds.

Holdout Gun
These are small pistols usually only seen a seedy under world, or so all the nobles who carry them would like everyone to believe. Any attempt to hide these weapons on your person get +4.

Blade Gun
Well, it was only a matter of time before someone thought to attach a short sword blade to a gun. The wielder must be proficient in both swords and guns to use this. The blade does a D6 in melee and has a 20x2 critical range.

Pintucker Pull-fire
Pintucker, the top name in gunsmiths. Hailed as the best gunsmith yet living, it is strange that he chooses to live in the port town of Teon. Here he produces some of the best light cannon and firearms in the north. The Pull-fire is just the most well known of his creations. Named for the way in which one ‘cocks’ the weapon it always counts as master worked. Also, a one rolled on a reload skill roll or an attack roll does not jamb the weapon.

Pintucker Twin Shot
Yet another creation form the skilled workmen under the direction of Thadic Pintucker, the Gnomish weapon smith. Basically it is a standard Pull-fire with a second barrel underneath the first. To fire the second barrel one just pulls farther back on the pull-pin and when you pull the trigger both barrels go off. Or you can set off one barrel, to save ammunition and gain another ten feet in range.

Cardhas Swivel gun
Named for a great general from history, and an ancestor of the company owner, the Cardhas is a pintle mounted light cannon used primarily as a close in ship defense. They are also often loaded with grape shot and used in boarding actions; it is this use that got them the nickname ‘deck sweepers’. These ‘guns’ have also been heavily used on the walls around the city of Tanton, indeed it was the huge order made by the city that gave Cardhas Cannon Works the money needed to become one of the largest makers of heavy armaments in the world. Their methods have been emulated by the rest of the world.
One noted use of these weapons is with the Knights of the Kings Own, the heavy battle armor they wear is heavily enhanced and they have several of these weapons modified to be used by hand. (As noted in the picture)The addition of a Fire Stone igniter on the underside and quick access to the barrel by way of a rotating breach allow one man to hold, load, and fire these weapons, but are so heavy that ONLY the great strength granted by battle armor allows them to be used by one man. But the great success in use by the Kings Own caused Cardhas to start a line of these weapons for use in a mobile pintle mount; a heavy iron base that is portable by a three man cannoneer squad.
Grape Shot: instead of a single blast line doing damage, these guns are often loaded with small grape sized iron balls. When this is used, this weapon does 3D6 of damage to all creatures in a thirty foot cone.

You may be wondering why there are no rifles or long arms in the setting presented here.
Well, truth be told, I didn’t want long arms and the inherent change in warfare they come with. What type of fantasy is one where a legion of elves die under a hail of bullets? There are sone fantasy settings that try to keep both the swords and guns but what happens is either the guns aren’t realistically powerful, or they are and no one can use a sword because they’d just get mowed down before they got in range. Neither was for me, I wanted the keep the sword play, and have guns be realistic. The way to do that was to take the most powerful versions, rifles, out of my setting. The other thing I wanted still include though was cannons, for great naval battles. So how to explain the absence of long arms, but not cannon or pistols, I asked and thought it over. The answer was the gunpowder itself.
Allow me to explain further. It started when I was watching a black powder rifle hunter clean his weapon. You see, standard gunpowder is corse and comes in rather large ‘chunks’ like sand rather than a fine powder and when it burns the dust from these ‘chunks’ his heated and fills the imperfections or rifling of the weapon. This residue must be cleaned from the weapon after every shot or the buildup will caus the weapon to jam, or worse, explode. In order to explain the absence of long arms and not cannon and pistols all I had to do was change the gun powder. In stead of large sand sized particles gunpowder, or rather ‘blastpowder’ is an incredibly fine material akin to the dust one gets when one files down steel. When you have such a fine material with the combustive power of gunpowder, it burns hotter and melts down more, caking to the inside of the barrel making it incredibly hard to clean out it every shot unless it is very short or wide enough to actually reach in and scrape out the build up.
And thus in my fantasy realm only the short barrels of pistols or the wide ones of cannon can be used safely.

Have you ever looked a the Iron Kingdoms Gun Mage class?

Because it's very similar to this, and is effectively a bard with a gun rather than music, mechanically at least. And I'm not sure if this is particularly superior.

yes i have seen the Gun Mage class, even played one.
however, the gun mage is it self a rip off of the Gun Gliph from Steam & Sorcery.
the Gun caster is just tailored to my campaign setting.