It's a simple-enough matter A firearm design either evolves to keep up with the needs of the user, or it becomes obsolete and falls by the wayside. Probably the best example of this is Browning's 1911. Similarly, the AR-15 has likewise evolved in an amazing manner to keep up with the needs and desires of its end-users.
From a lightweight combat rifle sent to battle Kalashnikov's Avtomat in the jungles of Southeast Asia, the AR-15 has continually evolved down through the decades. From being considered a poor joke in the accuracy department, it has gone on to drive the M14 from the 600-yard line in NRA High Power. Scoffed at for being a "poodle shooter," the AR has grown fangs and is now available in a variety of calibers, including bigbores like the .458 SOCOM and .50 Beowulf. Its ergonomics and accuracy have allowed it to dominate three-gun and steel-plate matches. Today ARs ride in an increasing number of patrol cars, and M16A2s, A4s and M4 carbines are turning live terrorists into dead ones in Iraq and Afghanistan.
Without a doubt, the AR hasn't stood in one place for very long. With the surge of research-and-development work due to our war on terror and the recent demise of the assault weapons ban, the AR-15 is more popular today than ever. So let's take a look at where the venerable AR is headed.
Brass And Bullets
One of the most exciting changes to take place in recent years for the AR has been the introduction of both improved ammunition and entirely new chamberings.
Without a doubt, the driving force in improving the performance of the .223 has come from Service Rifle competition. With the 55-, 62- and 69-grain bullets unable to compete with the .30-caliber 168-grain Sierras at 600 yards, service-rifle shooters clamored for something better. This they eventually got in the form of 75-, 77-, 80- and 90-grain match bullets. Overnight the .223 went from being a 300-yard gun to being able to hold its own against the .308 at 600 yards and beyond.
One company that took the lead in this area was Black Hills Ammunition. Due to its quality and consistency, Black Hills quickly won every contract for .223 match ammo for every branch of the Armed Forces. When the war on terror began and our Special Forces needed a long-range load for the new SPR, they simply fielded 77-grain Black Hills Match loads.
Designated MK 262 Mod 0, this load quickly earned an enviable reputation in Afghanistan for excellent accuracy and superior terminal performance. Kills were made with this load out to 700 meters, and in one engagement two SF operators armed with SPRs killed 75 Taliban with 77 rounds. Upgraded to become the current MK 262 Mod 1, this load features a 77-grain Sierra MatchKing with a cannelure for reliable operation in full-automatic weapons.
While you cannot buy MK 262 Mod 1 ammunition, you can purchase 77-grain match ammo from Black Hills. This load is almost identical except for the lack of a cannelure and no crimp on the primer.
While MK 262 Mod 1 gets the glory, Hornady's 75-grain TAP load is also making its presence felt in Afghanistan and Iraq. Also in use by certain Special Forces units, Hornady's 75-grain HPBT TAP load features a 75-grain Match bullet and offers improved terminal performance and superior accuracy compared to the standard-issue 62-grain M855 Green Tip.
Today, though, the AR is no longer confined to only the .223 cartridge. Current models are chambered in a wide variety of pistol and rifle calibers. In this regard probably the most interesting are the 6.5mm Grendel, 6.8x43mm SPC, .458 SOCOM and .50 Beowulf. Both the 6.5mm Grendel and 6.8x43mm SPC are modern intermediate cartridges based on existing cases.
Developed by Alexander Arms, the 6.5mm Grendel is based on a PPC case and throws bullets weighing from 90 to 144 grains. The standard load drives a 123-grain Lapua Scenar at 2,650 fps. Thanks to a very high ballistic coefficient, this load has less drop and wind drift than a 175-grain Sierra from a .308 out past 1,000 yards.
The 6.8x43mm Special Purpose Cartridge was developed by the 5th SFG as a CQB round. Firing a 115-grain OTM bullet, this cartridge was designed to offer superior terminal performance compared to the 5.56 M855 ball round. This it does quite handily.