9×19mm Parabellum in the context of "Heckler "

The Heckler & Koch HK33 is a 5.56mm assault rifle developed in the 1960s by West German armament manufacturer Heckler & Koch GmbH (H&K), primarily for export.

Building on the success of their G3 design, the company developed a family of small arms (all using the G3 operating principle and basic design concept) consisting of four types of firearms: the first type, chambered in 7.62×51mm NATO; the second, using the Soviet 7.62×39mm M43 round; the third, chambered in .223 Remington and 5.56×45mm NATO; and the fourth type, chambered for the 9×19mm Parabellum pistol cartridge. Commercially the HK33 was a successful design but it did not sell as well as the G3.

A fully powered cartridge, also called full-power cartridge or full-size cartridge, is an umbrella term describing any rifle cartridge that emphasizes ballistics performance and single-shot accuracy, with little or no concern to its weight or recoil. The term generally refers to traditional cartridges used in machine guns, bolt action and semi-automatic service rifles and select fire battle rifles prior to, during and immediately after the World Wars and into the early Cold War era, and was a retronym originally made to differentiate from intermediate-power rifle cartridges that gained widespread adoption into military service after World War II.

Full-power cartridges often have a caliber comparable to or greater than 7.5 mm (0.30 in) and a maximum effective range of at least 800 m (870 yd), and are intended for engaging targets beyond 300 m (330 yd). However, cartridges with calibers as narrow as 6.5 mm (0.26 in) have been described as being a full-power rifle cartridge. According the cartridge's overall length (COL), full-power cartridges can be grouped into long-action or "standard-action" cartridges, which are traditional cartridges (exemplified by the .30-06 Springfield, 8mm Mauser and 7.62×54mmR) with a COL between 72 and 85 mm (2.8 and 3.3 in); and short-action cartridges (such as the .308 Winchester and 6.5mm Creedmoor), which have a COL between 57 and 72 mm (2.2 and 2.8 in) and largely replaced long-action cartridges as battle rifle service ammunitions since the Cold War. Cartridges with a COL above 85mm are often however considered magnum cartridges instead of "full-powered".

An intermediate cartridge is a rifle/carbine cartridge that has significantly greater power than a pistol cartridge but still has a reduced muzzle energy compared to fully powered cartridges (such as the .303 British, 7.62×54mmR, 7.65×53mm Mauser, 7.92×57mm Mauser, 7.7×58mm Arisaka, .30-06 Springfield, or 7.62×51mm NATO), and therefore is regarded as being "intermediate" between traditional rifle and handgun cartridges.

As their recoil is significantly reduced compared to full-power cartridges, fully automatic rifles firing intermediate cartridges are relatively easy to control. However, even though they are less powerful than a traditional full-power cartridge, the external ballistics are still sufficient for an effective range of 300–600 metres (330–660 yd), which covers most typical infantry engagement situations in modern warfare. This allowed for the development of the assault rifle, a type of versatile selective fire small arms that is lighter and more compact than traditional battle rifles that fire full-power cartridges.

An ogive (/ˈoʊdʒaɪv/ OH-jyve) is the roundly tapered end of a two- or three-dimensional object. Ogive curves and surfaces are used in engineering, architecture, woodworking, and ballistics.

The SIG Pro is a series of semi-automatic pistols manufactured by SIG Sauer in Exeter, New Hampshire. It became the first polymer-frame handgun from SIG Sauer and one of the first pistols to feature a built-in universal accessory rail and interchangeable grips. Offerings in the series are chambered in .40 S&W, .357 SIG, or 9×19mm Parabellum. As of March 2020, only the SP 2022 variant was still listed on the SIG Sauer website. The SIG Pro was marketed as a lightweight and compact alternative to the "legacy" SIG Sauer handguns in an increasingly competitive and budget-oriented law enforcement market.

The .45 ACP (Automatic Colt Pistol), also known as .45 Auto, .45 Automatic, or 11.43×23mm is a rimless straight-walled handgun cartridge designed by John Moses Browning in 1904, for use in his prototype Colt semi-automatic pistol. After successful military trials, it was adopted as the standard chambering for Colt's M1911 pistol. The round was developed due to a lack of stopping power experienced in the Moro Rebellion in places like Sulu. The issued ammunition, .38 Long Colt, had proved inadequate, motivating the search for a better cartridge. This experience and the Thompson–LaGarde Tests of 1904 led the Army and the Cavalry to decide that a minimum of .45 caliber was required in a new handgun cartridge.

The standard-issue military .45 ACP cartridge uses a 230 gr (15 g; 0.53 oz) round-nose bullet at approximately 830 ft/s (250 m/s) fired from a government-issue M1911A1 pistol. It operates at a relatively low maximum chamber pressure rating of 21,000 psi (140 MPa), compared to 35,000 psi (240 MPa) for both 9mm Parabellum and .40 S&W, which due to a low bolt thrust helps extend the service lives of weapons. Since standard-pressure .45 ACP rounds are subsonic when fired from handguns and submachine guns, it is a useful caliber for suppressed weapons as it lacks the sonic boom inherent to supersonic rounds.

A hollow-point bullet is a type of expanding bullet which expands on impact with a soft target, transferring more or all of the projectile's energy into the target over a shorter distance.

Hollow-point bullets are used for controlled penetration, where overpenetration could cause collateral damage (such as aboard an aircraft). In target shooting, they are used for greater accuracy due to the larger meplat. They are more accurate and predictable compared to pointed bullets which, despite having a higher ballistic coefficient (BC), are more sensitive to bullet harmonic characteristics and wind deflection.

The Small Arms Protective Insert (SAPI) is a ceramic ballistic plate used by the United States Armed Forces. It was first used in the Ranger Body Armor and Interceptor Body Armor, both are ballistic vests. It is now also used in the Improved Outer Tactical Vest as well as the Modular Tactical Vest, in addition to commercially available "plate carriers". The Kevlar Interceptor vest itself is designed to stop projectiles up to and including 9×19mm Parabellum submachine gun rounds, in addition to fragmentation. To protect against higher-velocity rifle rounds, SAPI plates are needed.

A magazine, often simply called a mag, is an ammunition storage and feeding device for a repeating firearm, either integral within the gun (internal or fixed magazine) or externally attached (detachable magazine). The magazine functions by holding several cartridges within itself and sequentially pushing each one into a position where it may be readily loaded into the barrel chamber by the firearm's moving action. The detachable magazine is sometimes colloquially referred to as a "clip," although this is technically inaccurate since a clip is actually an accessory device used to help load ammunition into the magazine or cylinder of a firearm.

Magazines come in many different shapes and sizes from integral tubular magazines on lever-action and pump-action rifles and shotguns that may hold more than 5 rounds to detachable box magazines and drum magazines for automatic rifles and light machine guns that may hold more than 50 rounds. Various jurisdictions ban what they define as "high-capacity magazines".

The 7.92×33mm Kurz (“short” in German) (designated as the 7.92 x 33 kurz by the C.I.P.) is a rimless bottlenecked intermediate rifle cartridge (German: Mittelpatrone) developed in Nazi Germany prior to and during World War II, specifically intended for development of the Sturmgewehr 44 (assault rifle). The ammunition is also referred to as 7.9mm Kurz (German: Kurz meaning "short"), 7.9 Kurz, 7.9mmK, or 8×33 Polte. The round was developed as a compromise between the longer 7.92×57mm full-power rifle cartridge and the 9×19mm Parabellum pistol cartridge.