Question: What was designed by Georg Luger and manufactured by Colt? 
Context: The Colt New Line was a single action pocket revolver introduced by the Colt's Patent Fire Arms Manufacturing Company in 1873.  Two years after the Colt House Revolver (1871), a year after the Colt Open Top (1872) and almost simultaneously alongside the Colt Peacemaker (1873), the Colt New Line was one of the first metallic cartridge rear-loading revolvers manufactured by Colt's.  It was, alongside the Colt Open Top Pocket Model Revolver (1871), one of the first pocket metallic cartridge revolvers made by the company. The Colt Open Top Pocket Model Revolver was a single action pocket revolver introduced by the Colt's Patent Fire Arms Manufacturing Company in 1871.  Introduced a year before the Colt Open Top (a model from 1872) and two years before the Colt Peacemaker and the Colt New Line(both introduced in 1873), the Colt Open Top Pocket Model Revolver was, alongside the Colt House Revolver, one of the two first metallic cartridge rear-loading revolvers manufactured by Colt's.  It also was one of the first pocket metallic cartridge revolvers made by the company. The Borchardt C-93 ("Construktion 93") semi-automatic pistol was designed by Hugo Borchardt (1844–1921) in 1893 based upon the Maxim toggle-bolt design.  Borchardt also developed the high-velocity bottlenecked 7.65×25mm Borchardt cartridge for the C-93.  Borchardt's assistant at the time, Georg Luger, also claimed to have influenced its design.  Machine tool manufacturer Ludwig Loewe & Company of Berlin, Germany, produced the C-93 in anticipation of military orders.  With about 1,100 manufactured by Loewe and nearly 2,000 more produced by Deutsche Waffen und Munitionsfabriken, the Borchardt C-93 was the first mass-produced semi-automatic pistol. The 7.65×21mm Parabellum (designated as the 7,65 Parabellum by the C.I.P. and also known as .30 Luger and 7.65mm Luger) is a pistol cartridge that was introduced in 1898 by German arms manufacturer Deutsche Waffen und Munitionsfabriken (DWM) for their new Pistol Parabellum.  The primary designers were firearms designers Georg Luger and Hugo Borchardt, who developed the round from the earlier 7.65×25mm Borchardt while working at DWM. The Colt Model 1839 Carbine is an early percussion revolving smoothbore carbine manufactured by the Patent Arms Manufacturing Company between 1838 and 1841.  Produced alongside the Colt Second Model Ring Lever rifle (preceded by the First Model Ring Lever rifle, Samuel Colt's first manufactured firearm), the Model 1839 was the most popular longarm of the Patent Arms period.  The Model 1839 Carbine is differentiated from Colt's Ring Lever rifles by the lack of a cocking ring lever and the presence of an external hammer, which, when manually cocked, would rotate the six-shot cylinder to the next position.  Approximately 950 Model 1839 Carbines were manufactured, and an additional shotgun variant, the Model 1839 Shotgun, was produced from 1839 to 1841 with approximately 225 manufactured.  Though the United States Navy and Texas Navy purchased a number of Model 1839 Carbines, sales suffered due to the gun's high price and quality control issues. The Colt 9mm SMG is a 9×19mm Parabellum submachine gun manufactured by Colt, based on the M16 rifle. The family of Colt Pocket Percussion Revolvers evolved from the earlier commercial revolvers marketed by the Patent Arms Manufacturing Company of Paterson, N.J.  The smaller versions of Colt's first revolvers are also called "Baby Patersons" by collectors and were produced first in .24 to .31 caliber, and later in .36 caliber, by means of rebating the frame and adding a "step" to the cylinder to increase diameter.  The .31 caliber carried over into Samuel Colt's second venture in the arms trade in the form of the "Baby Dragoon"-a small revolver developed in 1847–48.  The "Baby Dragoon" was in parallel development with Colt's other revolvers and, by 1850, it had evolved into the "Colt's Revolving Pocket Pistol" that collectors now name "The Pocket Model of 1849".  It is a smaller brother of the more famous "Colt's Revolving Belt Pistol of Naval Caliber" introduced the same year and commonly designated by collectors as the "1851 Navy Model" (and which was a basically a larger, .36 caliber of the Pocket Model, "belt pistol" referring to a weapon sized to fit into a belt holster, as opposed to the saddle holsters generally called for by Colt's larger cavalry combat models).  In 1855 Colt introduced another pocket percussion revolver, the Colt 1855 "Sidehammer", designed alongside engineer Elisha K. Root. The 9×19mm Parabellum, also known as 9 mm Luger by the C.I.P. or 9 mm NATO by NATO (abbreviated 9mm, 9mmP, 9×19mm or 9×19) is a cartridge that was designed by Georg Luger and introduced in 1902 by the German weapons manufacturer Deutsche Waffen und Munitionsfabriken (DWM) (German Weapons and Munitions Factory) for their Luger semi-automatic pistol. The Colt Model 1903 Pocket Hammer was a short-recoil, semi-automatic pistol, designed by famous American arms designer John Browning.  It was a compact version of the Colt Model 1902 Sporting Model pistol derived from the original Colt M1900.  The Colt M1902 Sporting Model and 1903 Pocket Hammer model have significant differences to the military inspired Colt 1902 Military Model although they fire the same cartridge.  Its design is in no way related to the Colt Model 1903 Pocket Hammerless or the FN Model 1903 pistol. The Colt Machine Gun-1 or CMG-1 was an open bolt belt-fed machine gun that fired 5.56×45mm cartridges designed by Colt Manufacturing Company in 1965.  Colt hastily developed the CMG-1 to complement the CAR-15, a Colt branding of the M16 rifle, so that Colt might offer both of them as an alternative to the Stoner 63 weapons system.  It failed to achieve any sales, and was replaced by the Colt CMG-2, which also failed to achieve any sales.
Answer: 9×19mm Parabellum