and named it an M16A1GL - or an M16 with a curved magazine & Grenade launcher.
Okay, perhaps I'm exaggerating the birth of a new BrickArms prototype, but he did put a "birth announcement" on Flickr this morning to let everyone know we'll be getting some of these at ToyWiz soon!
So let's talk about this gun - it is a wildly popular one in our new prototypes, and a little history shows why.
The M16 was used by the US Military starting in 1963 and quickly became the standard service rifle in the Vietnam war. Ever since then, it has remained the primary service rifle for all branches of the US Armed Forces, and is widely used by militaries world-wide. Wikpedia estimates that over 8 million M16's, in both full-automatic and semi-automatic versions have been made. In 2010, however, the M16 began to be phased out in favor of the M4 Carbine, which BrickArms already produces in it's regular line.
Will remains true to history with this new incarnation of his prototype too - a grenade launcher was produced to be mounted on the M16. And if you noticed that he produced both straight and curved magazines - good eye. The difference between the two is that the short, straight magazine is like the 20-round versions used during the Vietnam War. The longer, curved magazine is a more modern style that is in current use, and holds 30 rounds.
Ultimately, this BrickArms version of the M16 has uses for almost any military builder, and also for fans of modern combat games like Call of Duty. Of course, Will created the specific model M16A1 for his prototype, but it is similar enough to other versions, especially at Lego size, to suffice in most builds. And for some builders - especially those wanting to make Vietnam War MOCs - this weapon is almost a necessity.
It is also a fantastic base piece for modifications. Because so many have been produced for so long, there have been many variations of the M16 in service, and it wouldn't be out of place to mod it with different parts for specific purposes. If you wanted the M16 from prior to 1967, for example, removing the forward assist is a simple modification to attempt.
The Wikipedia entry for this weapon is a great starting point for research into how to modify your BAP into a weapon appropriate for your era, setting or conflict.