The AK 4 is a Swedish version of the German Heckler & Koch G3 assault rifle. It was selected during the early 1960´s to replace the Swedish submachine gun Kpist Mod 45 and the Swedish semi-automatic rifle AG 42 . The idea was to get a new and modern assault rifle with the impact and power as the AG 42 and the full auto capacity of the Kpist Mod 45. Among the competitors of the HK G3 assault rifle was the Belgian FN FAL and the American M 14 assault rifle. After a number of different test in various environments the HK G3 rifle was chosen and modified on 40 accounts and thereafter renamed to AK 4 ( in Swedish : Automatkarbin 4, in English Assault rifle 4 ).

The AK 4 is a selective fire assault rifle that fires the 7,62×51 mm cartridge (.308 Winchester). The rifle is magazine-fed and each magazine holds 20 rounds. The firing principle of the weapon is roller-delayed blow-back function. The AK 4 is a very accurate assault rifle that can with standard sights hit a stationary target at 500 meters. The cyclic rate of fire in full-auto mode is approximately 600 rounds per minute. The velocity of the projectile when leaving the barrel is 790 meters per second.

The AK 4 is available in the Swedish armed forces in three different types. They are :

• AK 4 A (Standard basic version)
• AK 4 B (New modification with red-dot sight, increased rate of fire and enhanced exterior surface)
• AK 4 OR (The basic version with a telescopic sight with 4x enhancement)

The AK 4 can also be fitted with a grenade-launcher .

The AK 4 has now been more or less replaced in the Swedish Armed Forces by the lighter and smaller caliber AK 5 (5,56 mm, .223 Remington). But the AK 4 is still in service with the Swedish Home Guard and some other army units.

Technically, the H&K G3 has inherited much of its basic functionality from the nazi-era MP 44 (Or StG 44 - Sturmgewehr 44). The makers of the MP 44 formed the joint stock company Heckler & Koch shortly after the war, and retained much of the by then proven technology in newer automatic rifles.

The main drawback of the G3 and AK4 lies in the choice of caliber: it is a superb weapon as a rifle, but impossible to handle in automatic mode, or even in short bursts. Smaller caliber, but high velocity, assault rifles like the AK74, the Ak5, the M16 or the Galil are much easier to handle in combat-like situations.