The RPG-7 (Russian: РПГ-7) is a portable, reusable, unguided, shoulder-launched, anti-tank rocket-propelled grenade launcher. Originally the RPG-7 (Ручной Противотанковый Гранатомёт – Ruchnoy Protivotankoviy Granatomyot – Hand-held anti-tank grenade launcher) and its predecessor, the RPG-2, were designed by the Soviet Union; it is now manufactured by the Russian company Bazalt. The weapon has the GRAU index 6G3.

The ruggedness, simplicity, low cost, and effectiveness of the RPG-7 has made it the most widely used anti-armor weapon in the world. Currently around 40 countries use the weapon, and it is manufactured in several variants by nine countries. It is popular with irregular and guerrilla forces. The RPG has been used in almost all conflicts across all continents since the mid-1960s from the Vietnam War to the early 2010s War in Afghanistan.

https://en.wikipedia.org/wiki/RPG-7

RPG 7: full disassembly & assembly
https://www.youtube.com/watch?v=Ht9W5xGFEA8

This video was made with the help of the game World of Guns: Gun Disassembly:
http://store.steampowered.com/app/262410/