This Star Wars papercraft is a EE-3 Carbine Rifle, created by tektonten. The EE-3 carbine rifle was a blaster that was modeled after the E-11 blaster rifle used by Imperial Stormtroopers or posibly vice vesa. The rifle consisted of a small handle attached to a long circular barrel. An alternate version of this model features a modified scope mounting and hand grips that run the length of the barrel.
The EE-3 was used famously by the bounty hunter Boba Fett. Fett modified his by adding a stock and an electronic scope for distance shooting, making it a dangerous weapon. Prince Xizor also used an EE-3 to try to kill Luke Skywalker as the Jedi and his friends escaped the Falleen's palace on Coruscant. Another user of this weapon was the Zabrak bounty hunter Sugi, who wielded it during the Clone Wars. Kiera Swan also used this weapon in the Box. The EE-3 is also the standard issue weapon for the Mandalorian Protectors.
In Star Wars: Battlefront II, the rifle discharges a three-round burst. Note also that in the game, Fett's blaster uses the same graphics as the E-11 Blaster Rifle. It is likely, however, that this was simply done to save memory space on the disk, as many similar situations take place with Jango Fett, Leia Organa, and other characters.
The prop Boba Fett uses in the films is a modified Webley & Scott № 1 Mark "I" Flare Gun, built for use by British troops during WWI. To make it into the weapon of an intergalactic bounty hunter, prop makers added a rifle scope, some detail parts to the stock and either an MPP Microflash or Heiland Synchronar flash unit (the same models used for Darth Vader’s Lightsaber) protruding from the end of the barrel. There were also some blocky detail pieces added between the scope mounts and the body of the gun.
The barrel of the gun was chopped of by a clone of Starkiller's. Yet, later, in Star Wars Episode VI: Return of the Jedi it happens again.
In Star Wars Episode VI: Return of the Jedi, the Webley & Scott was used again, only this time more detail was added, primarily to the barrel. Presumably this was because the prop would be featured prominently in the skiff battle scenes where Luke Skywalker slices it in half with his lightsaber. The Heiland flash unit was gone and a beefier barrel with ribbed hand grips was built over the existing flare gun barrel. The same scope was used, but for some reason it was mounted pointing in the opposite direction from the Star Wars Episode V: The Empire Strikes Back version. The scope was also mounted farther back on the gun and slightly lower. The blocky detail parts on the scope mounts were also eliminated.
In 2010, "Bounty Hunters," an episode of the Star Wars: The Clone Wars television series, showed a bounty hunter wielding an EE-3. Because the series takes place before 19 BBY, and the EE-3 was established to be modeled after the E-11, an Imperial stormtroopers' weapon that was first manufactured around the time of the Galactic Civil War, the weapon's portrayal in the show creates a continuity error. Likewise, the EE-3 later reappeared in the show in the episode "The Box." To date, the inconsistency remains.
You can download this star wars paper model template here: Star Wars - Full Size EE-3 Carbine Rifle Free Paper Model Download