The 5.56x45mm NATO round is a micro-caliber rifle round based upon the .223 Remington loading. In the US military, it is known as the M855A1 in it's most recent incarnation. In the rest of the world the 5.56x45mm NATO is known as the SS109.
Originally, the 5.56x45mm was designed with two goals in mind: Incapacitation, and weight reduction. The round was designed to wound a soldier, rather than kill them outright like the 7.62x51mm NATO round that came before it, as it would take two more soldiers out of the fight to take care of them.
Not only this, but the 5.56x45mm NATO is shorter and lighter than the 7.62x51mm NATO round that was it's predecessor, allowing troops to carry more ammunition.
The 5.56x45mm NATOround, also called the SS109, is the most commonly used Military-issue rifle round in the western world. However, it's usefulness has deteriorated against an enemy that does not value their lives, nor the lives of their comrades.
One of NATO's military firearm calibers. The 5.56x45mm NATO catridge is used pretty much only for allied (America, UK, France, Germany, etc) assault rifles.
China even uses this caliber for their T95 battle rifle.
Nickname given to bales of marijuana thrown overboard or out of airplanes. Origin is reportedly from members of the US Coast Guard in the area of Southern Florida.
A sunburn or suntan focused on the left arm. It is caused by the left side of the body being the only half that gets exposed to sunlight while driving. Presumably, it would be located on the right side of the body in countries where they drive on the left side of the road.
I had a trucker's tan after driving for 10 straight hours on a sunny day.