Quality is an investment in the future, and that very well applies to the weapons that the troops used throughout history. The development of weapons dramatically changed the course of warfare in the 20th century due to the combined lessons of the past and the technological advancements that continue to develop. Even when produced long ago, there are still infantry weapons still being used by the militaries of today all over the world, proof that quality is indeed an investment in the future. Here are some of them:

PK Machine Gun

In 1955, the Main Artillery Directorate of the Soviet Union adopted the specs requirements for a new 7.62 mm battalion-level and general-purpose machine gun to be chambered for a rifle cartridge,

PK Machine Gun
PK Machine Gun (Warman, CC0, via Wikimedia Commons)

In 1958, G.I. Nikitin and Yuri Sokolov developed a machine gun prototype that successfully passed the field tests. A batch of their guns was manufactured in 1960 for service tests before production at the Kovrov Mechanical Plant. A team of Izhevsk Mechanical Plant designers led by the famed creator of the AK-47 also created the PK Machine Gun. Their version was a gas-operated rotary-bolt design based on the trusty Kalashnikov-pattern arms.

Their design was preferred because it was more reliable and cheaper to manufacture compared to the Nikitin-Sokolov one. So their PK went into production at the Kovrov Mechanical Plant.