In contrast to division of work, division of labour is the specialization of an individual workers' or organizations' skills, through education, training, and practice.
AR15 Trigger Upgrades. 1  The trigger is one of the most crucial elements in achieving the highest level of accuracy from any firearm. Installation of a quality trigger will permit a light pull with little or no creep and overtravel.
The U.S. Air Force and the U.S. Army adopted AR-15 variants (as the M16), and modified the .223 Remington cartridge slightly (by switching the powder to one that would produce a higher velocity), this cartridge becoming the 5.56x45mm NATO.ifle receiver extensions are used with fixed-stock AR-15 rifles, and are slightly longer than the carbine-length receiver extensions. The corresponding action spring is generally between 11.75 and 13.5 inches long; any shorter, and it should be replaced.