A firearm is a a normally tubular weapon or other device designed to discharge projectiles or other material.
A flintlock (フリントロック Furintorokku?) is a type of gun ignition mechanism that was first introduced in about 1630. It was a revolutionary design that replaced the firearm-ignition technologies at the time, such as the matchlock and wheel-lock.
The flintlock was renowned for becoming next to useless in the rain, but was a great improvement over the matchlock which required a lit slow-burning match cord that was impossible to keep lit in the rain. In damp weather, shooters would keep a cover of some sort over the lock to keep it dry until use. Most flintlocks had only one barrel and had to be reloaded from the muzzle after each discharge. Civilians typically used a powder-horn and ball bag to reload after each shot. In military use, soldiers used preload paper cartridges that contained both a measure of gunpowder and a ball (bullet) to speed up reloading. Due to the length of time it took to reload, most stationary gunmen using the weapon would carry several spares (often pistols) on them so they did not have to waste time reloading after each round. However, despite its downfalls, the flintlock was a favorite military weapon.
A musket was typically a military version of a flintlock. It was a smooth bore weapon into the early 19th century. Like all muzzle-loaders, it required a tedious reload, however cartridges (a paper tube pre-filled with powder and ball) sped up the process. A trained soldier could fire from 3 to 5 times a minute and carried several dozen cartridges in specially designed containers slung over the shoulder or on a belt about the waist. The flintlock musket was in use from colonial times into the first half of the 19th century. A rifled musket was a later military firearm that had spiral grooves in the barrel. The percussion cap rifled musket was the standard issue military firearm by the mid 19th century.
A cannon is an often large, heavy piece of artillery that uses explosive material, such as gunpowder, to launch projectiles of considerable size compared to bullets, such as cannonballs or bombshells. Cannons can be mobile or stationary, and may vary in size, sometimes requiring the operation of more than one individual to work properly. Cannons predated portable firearms for several years, having been an indispensable weapon in military and naval warfare through centuries due to their power and range.
The flintlock is the main gun type seen in the series. They are much more advanced than the traditional flintlocks of real life, in that they do not suffer the same reloading time and limited rounds as found in the real life versions. Most of the flintlock weaponry in One Piece are also semi-automatic, something only found on a few exotic multi-barrelled volley gun designs in real life. Both Yasopp and Lucky Roo, along with many background characters, have been seen using these type of guns. The guns, however, still fire small, round, ball-like bullets like those used by the traditional guns until the last couple of centuries.
Cannons also see widespread use throughout the series, as practically every ship is equipped with at least one cannon as a defensive measure, be they Pirate or Marine ships. Marine cannons, however, appear to be more technologically advanced as they can function like gun turrets, allowing for better aiming. Cannons are also commonly found in other military structures such as Marineford.
Types of FlintlocksEdit
Because of the more advanced structures of the standard flintlock, there are other models and ammunition developed for use. Also, even standard flintlocks may be customized in physical appearance to suit one's motif.
- Flintlock .44 Caliber 6 Shot Revolver (フリントロック式44口径6連発リボルバー Furintorokku Shiki Yonjūyon Kōkei Rokurenpatsu Riborubā?): A new model from the South Blue, capable of rapid-fire with six chambers. Used by Mr. 5, who provides ammunition via his Devil Fruit powers.
- Yellow Gun (黄色い銃 Kīroi Jū?): A pistol shaped like the number "7", and is designed to fire dice-shaped bullets that explode on impact. Used by Mr. 7.
- Gero Gero Gun (ゲロゲロ銃 Gerogero Gan?): A pistol with a muzzle shaped like a frog's head, and fires frog-shaped bullets that explode on impact. Used by Miss Father's Day.
- Flash Guns (閃光銃（フラッシュガン） Furasshu Gan?): Dual-barreled flintlocks with ornate design, and Flash Dials installed within to hide the shots with a flash. Braham uses two of them.
- Walker 36 Caliber Percussion Revolver (?): A powerful handgun. One owned by Charlotte Pudding, who loaded hers with "candy-jacketed bullets"
- Some flintlocks are installed with dual barrels, allowing two rounds per shot. Krieg wields two of them while Caesar Clown wields one.
- Igaram has multiple gun barrels installed into his hair curls.
- Nero wielded a pair of derringer flintlocks to compensate his lack of Shigan.
- World Nobles wield gold-plated single-barreled pistols. Aside from its more grandiose-color, it functions no different than the standard flintlock. Saint Charloss wielded such firearm, and (in the anime) so did Saint Mjosgard.
- Donquixote Doflamingo wields a single-barreled, obsidian black pistol with luxurious gold plating. He loaded it with lead bullets to inflict lead poisoning.
- Vito wields a pair of large, black revolver flintlocks.
- Capone Bege used a flintlock to shoot Pekoms.
- Hody Jones killed Otohime with a rifle.
- Foxy wields a rifle.
Other Types of FirearmsEdit
Aside from the standard flintlocks and muskets (along with their modified variants), there are other type of guns introduced in the series, though they appear rarer than the flintlock. Most of their designs are based off of the flintlocks, bearing the appearance and mechanism that fits the older times.
- Gin's shotgun, containing dual-barrels.
- Krieg's Needle Machine Gun, firing sharp stakes at a rapid rate.
- Mr. 4's giant gun, which bears resemblance to a hand-cannon or bazooka, and "fed" a Zoan-class Devil Fruit.
- Van Augur's special rifle, Senriku, possesses tremendous range.
- Wiper's bazooka, equiped with Breath Dial.
- Genbo's bazooka.
- Franky's machine-guns, amongst his built-in weaponry.
- Absalom's arm-mounted bazookas, which seems to fire based on his hand movements.
- Duval's harpoon guns, loaded with scorpion-venom laced ammunition.
- Roswald's cane gun.
- Rindo's bazooka, which is equipped with giant harpoons in lieu of actual explosive rounds.
- Jalmack's bazooka, which takes the form of a gigantic rifle and equipped with a cross-hair.
- Pell, Caribou, Coribou, Miss Friday  and Baby 5 all wield Gatling guns, Caribou's uses a crank mechanism.
- Hammond wields a rifle modified to fire trawl nets.
- Scotch's right arm.
- Gladius has firing mechanisms equipped on his arms to fire bullets powered by his Devil Fruit powers.
- Gotty's right arm.
- Both Capone Bege and Kelly Funk have access to Tommy guns.
Translation and Dub IssuesEdit
4Kids reaction to the presence of the guns is to color them green (or blue in a few cases), remove them, or turn them into something else (hammer-gun, arrows, Super Soakers, or cork gun). However, it should be noted this is a common edit with all guns, not simply flintlocks.