Once vilified by military and civilians alike, the M16 (and its civilian cousin, the AR-15) has undergone an amazing evolution and enjoys widespread support from both camps today. Despite heavy legislation in recent years against "assault weapons," the popularity of the rifle seems to be at an all-time high.

With the escalation of the arms race on the streets of America, the law enforcement community has responded by better arming itself. From patrol officers and sheriff's deputies carrying carbines and heavy-barrel H-Bar weapons in their patrol cars to tactical teams deploying other variants to fit their needs, the AR-15 is the dominant rifle in law enforcement.

Police SWAT teams generally provide three functions during an emergency call-out. These highly trained units provide containment, sniper/observer capabilities and entry/reactionary functions; the AR-15 is at home in all of these roles.

Containment requires the most versatility, so most weapons outfitted for this function generally reflect this, having shorter barrels, light mounts and possibly a red-dot sighting system of some type.

The sniper teams, on the other hand, often use a semiauto rifle or carbine, allowing the observer to provide protection for the team member actually looking through the scope of the bolt-action sniper rifle. For this, the chosen AR variants tend toward the fullsize H-Bar with or without a low-power optical scope.

The entry/reactionary teams have the obvious requirement of maneuverability for close-quarters combat. The dominant weapon for this work is the 9mm HK MP5, but AR variants are gaining popularity. Variants used for this role have short barrels, light mounts, are often fitted with a red-dot sighting system and are frequently full-auto.

This custom AR is a blend of Bushmaster, DPMS and other aftermarket parts. The 24-inch stainless fluted barrel free-floats inside a vented handguard. The high-rider flattop upper holds a 2.5-10X illuminated IOR Bucuresti scope at just the right height for the laminated thumbhole stock.

Optimally, an entry team has both .223 and 9mm weapons to best take advantage of the benefits of each. The issue of overpenetration is a significant worry to law enforcement, and generally it is undesirable to have rounds going through walls within a house. On the other hand, being trapped in a room when a suspect starts shooting at you through a wall requires a response in kind, and you definitely want a round that will go through the wall and retain enough energy to do its job.

It is a surprise to many people that the round that works best for going through walls is the 9mm. With relatively higher velocities, the .223 bullets generally break up upon impact, even when hitting a thin sheet of drywall. The resulting small fragments quickly lose their energy. Bullet selection plays a part in this, but even the toughest FMJ bullet tends to virtually disintegrate when it hits wood or drywall at 3,200 fps.

Colt And Clones
One reason there are so many choices within the AR-15 system is the number of quality manufacturers who have focused on it. ArmaLite, Bushmaster, Colt, DPMS, Olympic Arms and Knight's Mfg. Co. are some of the primary names in AR-15 weapons and parts. More recently, prominent custom gunmakers like Les Baer and Wilson Combat have begun making AR-15s. Each has contributed its own ideas toward the improved versatility of these guns.

One of the biggest advances was the advent of the flat-top design, which allows for the carry handle to be removed, leaving a Picatinny rail for secure mounting of optical sights This spurred an increase in the type, quality and variations in the sighting systems available. Other variations such as free-floating handguards, gas blocks without front sights and high-rise and left-handed upper receivers are just a few of the options that make this weapon so adaptable for many tactical teams across the country.

Both ArmaLite and Knight's have focused a great deal of attention on .308 caliber variations of the AR but at a corresponding jump in cost. At $1,500 to $3,000, these may well be the highest-priced variants in the AR family. Each of the manufacturers listed offers .223-caliber variations ranging from long, heavy-barreled "varminters" to short-barreled, collapsible-stocked M4-style guns.

Leupold's Mark 4 CQ/T 1-3x14mm has an illuminated reticle that is powered by a single AA battery. The power range makes the scope practical for both close-quarters combat and medium-range engagement.

Ammo For The SWAT Rifle
Despite the recent revolution of ultra magnums and short magnums in the hunting world, the cartridge scene in the tactical world has remained largely unchanged. Due primarily to the military use of the .308 Winchester and .223 Remington (or 7.62x51mm and 5.56x45mm, respectively), these calibers reign supreme in tactical use.

There are some notable exceptions, particularly within the military sniper area. This is with good reason. The military sniper's expected range is from long to extreme. The .308 in not a very impressive distance round, and teams that need to really reach out are calling on bigger, better rounds. Notable among these are the .300 Winchester Magnum, .338 Lapua, 7mm Remington Mag. and of course the .50 BMG.

Within the long-range-competition community, the 6.5-284 seems to have a fairly strong following, and some of the ballistic advantages of this round may propel it into use by some snipers. But don't hold your breath, at least in the law enforcement arena. Snipers are very resistant to change, and most have great confidence in the .308.

The role of the .223 in tactical operations for both law enforcement and the military is generally different than that of the .308 and other larger "sniper" rounds. Many police agencies have .223s available to their SWAT entry teams for use in close-quarters combat, as well as perimeter weapons. The .223 has proven itself as an effective defensive round, and the versatility of the weapons systems that support it lends it very well to the specific missions in which SWAT and some Special Forces units are deployed.

For the .308 sniper rifle, the 168-grain boattail hollowpoint match bullet is generally accepted as the standard round. The reason for this is quite simple: Shot placement is the most important aspect of stopping a threat. There is no argument that the BTHP (boattail hollowpoint) match bullet has been proven to be extremely accurate, but there are some new, highly accurate bullets available that may provide better terminal ballistics. Several of the ballistic-tip bullets are as accurate as the BTHP, and they offer more consistent terminal results in terms of rapid, yet controlled expansion along with significant penetration.

Law enforcement's dilemma is that it wants a golden bullet that defies physics. It wants an extremely accurate bullet that will smash through glass or any other medium that may separate personnel from their adversary, hit the suspect and immediately incapacitate him, and not overpenetrate, causing a potential threat to innocent bystanders. Until that magic bullet is found, I predict most will stay with BTHP rounds despite sacrificing some terminal performance available in ballistic-tip bullets.

This lineup of .308 ammo represents some of the best options available for tactical situations. Left to right: Black Hills 165-grain Ballistic Tip, Federal 150-grain Ballistic Tip, Winchester 168-grain Ballistic Silvertip, Federal 164-grain GameKing, Winchester 150-grain Fail Safe, Federal 165-grain Tactical, Federal 168-grain BTHP Match, Winchester 168-grain BTHP Match, Black Hills 168-grain BTHP Match (moly) and Black Hills 168-grain Limited Penetration.

There have been some people toying with the idea of switching to other calibers such as the .243, .260 Remington or the 7mm-08 to address these concerns. Lighter, faster bullets expand more rapidly, causing their damage earlier within the target and providing less overpenetration danger. This is not a good thing when you are hunting elk or moose, but there is some logic when facing smaller, thin-skinned adversaries.

Some teams address the wide range of variables they face by training with specialty ammunition to deal with certain circumstances. The need to shoot through glass might warrant the use of a proven controlled-expansion bullet such as the Trophy Bonded used in Federal's Tactical Load. Other situations may heighten the concern of overpenetration and warrant the use of a special frangible or limited-penetration-type bullet. One such round is Black Hills Ammunition's Limited Penetration load. Based on a 168-grain bullet designed by benchrest shooter and varmint-bullet maker Clint Starke, the round is designed to violently expand and fragment into small pieces that quickly lose their energy. I've tested the round in ballistic gelatin, and I was very impressed with how quickly the wound channel begins to expand (within the first inch of initial penetration), how impressive the wound channel is and the lack of deep penetration.

For many shooters, this may sound strange because we generally want deep penetration, but not for this unique application. This is clearly not a round for all occasions. The key is training and knowing where this round shoots in relation to the general-purpose round selected for the particular gun, because without shot placement, the rest doesn't matter.