It seems that the GTA V modding community is quicker when it comes to weapon development than the guys over at Heckler & Koch. They've been working on an experimental smart grenade launcher since the late 1990's. We'll bet putting this mod together took less time.
GTA V has seen some unique weapon mods in the past and the majority of weapon mods focus on real-life firearms. This may be the first time however that the game gets a working and fully animated version of a prototype weapon that is still being developed.
The United States Armed Forces has a penchant for drafting up weapon development programs despite several failures in the past. One of these botched programs was the Objective Individual Weapons Program. While the OIWP is dead and gone, several of the entrants spawned offshoot projects of their own. One of these projects is the surprisingly successful XM25 "Punisher" CDTE (Counter Defilade Target Engagement).
While still under development the weapon has made its way into several video games and three well known modders decided that it needs to be added to GTA V as well - because, you know, the game is hurting for more ways to efficiently take lives. Jridah, Rippler & Suspect, all of whom are very well known names in the GTA V modding scene have put quite a bit of work into what may be the most polished weapon mod for the game.
The GTA V XM25 CDTE has all the correct animations and functions. It is reloaded like it should be, it is held like it should be and it is shot like it should be. The texture is extremely high quality, and the scope is realistic as well. The sounds are unique and befitting the weapon.
Plus, you know, it goes boom.
What other examples of experimental or prototype weapons do you want to see make their way to GTA V?