Reloading options for this military/civilian round abound.
Do you know what common thread the .308 Winchester, .30-06 Springfield, .45-70 Government, and the .223 Remington share? Besides being the most popular sporting cartridges in their respective categories, they were all conceived and born to a life of government service. Each of these rounds has been used by the United States Armed Forces—and not coincidentally, immensely popular sporting calibers. Of the quartet, the .223 Remington is the youngest, first appearing in 1957. Perhaps appropriately, this Baby Boomer cartridge has bloomed later in life to become one of the most prevalent rounds on the shooting scene today. It can be found in everything from across-the-course high-power competition rifles to varmint rifles, and when reloaded properly, it performs well in all of those applications.
The .223 Remington was developed by Robert Hutton while working with Gene Stoner of Armalite in the late 1950s and early 1960s in an attempt to create a new military cartridge. The .222 Remington was ruled out for the military because it failed to meet the requirement of retained velocity greater than the speed of sound at sea level (approximately 1,190 fps at 68 degrees Fahrenheit) at 500 yards. But using a 55-grain boattail bullet developed by Sierra, Hutton was able to reach the velocity goal with the cartridge that would become the .223 Remington.
Called the 5.56mm NATO, it was adopted by the military in February 1964 and was released to the sporting public as the .223 by Remington one month later. The initial military loading was a 55-grain pointed boattail bullet with a muzzle velocity of 3,250 fps. In 1984 this was changed to a 70-grain pointed boattail bullet with a muzzle velocity of 3,150 fps.
The civilian .223 Remington annually appears in top-three lists of reloading die sales, and few, if any, rifle makers do not list at least one .223 Remington in their catalog. Even popular single-shot handguns such as the Thompson Center Contender are chambered for the .223 Remington. Accordingly, this round probably sees a more diverse listing of uses than any other round currently manufactured. It continues as a military round and is popular with civilian shooters of AR-15 and other quasi-military semi-auto rifles such as the Ruger Mini-14. Most makers of heavy barreled ultra-accurate varmint rifles chamber the .223 Remington in their rifles. It is highly favored in these rifles for shooting prairie dogs, gophers, and ground squirrels. In addition to its good accuracy and flat trajectory, these hunters love the .223 Remington for its mild recoil and report, light appetite for powder, and easy availability of components.
Predator hunters have found that the .223 Remington is all the cartridge they need out to 275 to 300 yards. It will consistently kill tough coyotes without destroying too much fur, even on foxes and bobcats. This is particularly true if you match the bullet to the expected target. Finally, the Service Rifle category of the National Match course is usually fired with a .223 Remington in an AR-15 rifle.
The Crucial Twist Rate Choice
In these various applications, rifling twist rates will vary a great deal. Most hunting rifles will have a 1-in-12 (or 1-in-14 in some early rifles) twist, while competition rifles are often as fast as a 1-in-7 twist. Some, such as the Colt HBAR Sporter, split the difference with a 1-in-9 twist. The twist rates are a prime consideration in reloading the round. A twist of 1-in-14 will not stabilize a 55-grain bullet very well, and at least a 1-in-12 rate is needed for bullets of this weight. The heavy bullets used for long-range target shooting, such as the 80-grain Sierra projectile, will require a 1-in-7 twist to stabilize. Any bullet of more than 60 grains will likely shoot better with at least a 1-in-9 twist.
Conversely, the 1-7 twist is too fast for most varmint-weight bullets and those designed for fragmentation on contact with the target. When fired at full velocity, the Speer TNT, Hornady SX or V-Max, or the Sierra Blitz will tear apart in flight from the centrifugal force of the too-fast rotational velocity. I have fired Hornady 40-grain V-Max factory loads in a Colt HBAR with a 1-in-9 twist with excellent results. This twist should provide a good compromise for shooters looking to use the long 60- to 70-grain bullets while still providing excellent results with bullets as light as 40 grains.
.223 Case Selection And Preparation
Military cases are plentiful and readily available. They can be used with good results, but the primer crimp must be removed with one of the many tools designed for this task. It is also advisable to condition the primer pocket and flash hole with the RCBS Trim Mate Case Prep Center. If you are going to be using the ammo in a semi-auto, it is a good idea to crimp the bullets. To get a consistent crimp, the necks must be trimmed to a common length. After trimming, you must chamfer the mouth inside and remove the burrs on the outside. Despite what some reloading-equipment manufacturers claim, you cannot crimp a bullet without a cannelure and expect good results. Several manufacturers offer bullets with cannelures, and you should always use one if you are going to crimp.