Magazine release
The control on a firearm that retains the weapon's magazine.
Types
Pistol:
Heel or "European" magazine release is located at the butt of the pistol grip and is commonly a simple catch as on the Makarov or Walther PPK. This has the advantages of being both ambidextrous and resistant to inadvertent release. Its primary disadvanteges are a slower reload in good conditions and often the requirement for greater force to activate compared to the other systems.
The thumb release located at the junction of the trigger guard and pistol grip as typified by that on the Colt M1911A1 or Browning HP is common on American designed pistols and those for the American market. It has the advantage of speed in reloading while compromising some on the risk of accidental risk of dropping the magazine and the requirement to have either comparatively long thumbs or changing the hold on the weapon to actuate it.
A variant of the thumb release is the use of a lever, often ambidextrous, in lieu of a button as found on the Ruger P-series pistols and Walther P99. This allows the use of either thumb or the use of a finger to activate the release mitigating the disadvantages of the Browning design.
A less common design is a button along the lower edge of the pistol grip like the Micro-Uzi Pistol or the early models of the Beretta 92 and Beretta 93R. These are intended to be activated by the left thumb and are usually intended for the use of magazines that extend below the base of the grip.
Non-traditional pistols like the Heckler & Koch SP89, TEC-9, Škorpion vz. 61, and others often have magazine releases more similar to longarms.
Longarms:
Push button magazine releases as found on the L85-series and M16-series weapons are common and usually are found only on one side of the weapon, protected by a ridge or other protection against inadvertent activation. This may limit speed of reloading in certain positions or produce a slower reloading when fired left handed. (In the case of the L85, this is somewhat intentional as the weapon is designed to fire only right handed.) The disadvantages of this design are improperly protected buttons, decreased ambidexterity, and the requirement for some degree of fine motor control and precision to operate it under stress.
A paddle or lever magazine release like that on the AK-series and US M14 rifle is located behind the magazine and is often found on designs where the magazine must be cammed into pace. It is ambidextrous, simple, and located very close to the magazine which simplifies loading. Its disadvantage is the increased force required to activate it and often the requirement to manually remove the empty magazine instead of simply letting it drop free.
Some firearms combine both systems like the Heckler & Koch MP5 and G3-series weapons providing the option of using either variation.
