Starting in the late 1990s, as the paradigm in terms of small arms needs in modern warfare changed, mid-sized and short-barrel carbines originarily used only by airborne personnel, vehicle crews and special forces went on to become standard issue for infantry forces.

As usual, the U.S. Armed Forces led the way with the adoption of the 14.5"-barrel M4A1 carbine as a general replacement for the 20-inch M16 rifle.

At the same time, short-barrelled and mid-length carbines earned increasing consideration among civilian shooters, and same goes for law enforcement – particularly in urban areas, where a 20-inch barrel rifle would be unpractical to handle.

In many jurisdictions – particularly in the United States – law enforcement officers do not enjoy a special status, half-way among civilians and military like in Europe, but are considered civilians just any average citizen; as such, their standard issue firearms are normally the same available for commercial sales, while select-fire weaponry is generally available only to SWAT-like units.

If you are among the mentioned categories of users and if you're evaluating the purchase of an AR-15 based carbine, now Colt has a very interesting alternative – among all others. The Colt Defense M4 Classic Series is the commercial version of the Colt Law Enforcement Carbine line – a group of straightforward semi-automatic versions of the M4 weapon system used by the U.S. Armed Forces.

The Colt Defense M4 Classic Series includes two variants: the M4 Carbine Classic Series is a commercial version of the M4A1 carbine, sporting a 14.5" barrel and an A3 upper receiver with removable carrying handle installed on a MIL-STD 1913 Picatinny rail.

Caliber is 5,56x45mm; the Colt M4 Classic Series carbines will properly stabilize any civilian or military .223 Remington and 5,56mm load. Feeding is through STANAG magazines, and a single metal 30-round one is issued with each sample.

All that tells the two versions apart is the barrel length: 12 inches for the Commando, 14.5 inches for the Carbine. In either case, barrels are cold-hammer forged and chrome lined, offer six right-handed grooves with a 1:7" pitch, and a Birdcage-type flash hider affixed to a threaded muzzle.

The 14.5" barrel of the Carbine version also comes with the signature "Step Cut" that dubs as an attachment point for the M203 grenade launcher in the select-fire models and has no function in the civilian version other than aesthetics.

All upper and lower receivers are forged out of Type III black hard-anodized, 7075-T6 lightweight aircraft-grade aluminum alloy. The controls configuration is not ambidextrous like on most commercial AR-15 variants, but reprises that found on military-issue models – something that will undoubtedly appeal the purists. Same goes for the furniture: the pistol grip, four-position collapsible stock and two-halves handguard with aluminum heat shield are the same normally found on the M4A1 service carbine.

Unlike the Colt Expanse M4 we described a few weeks ago, the Colt Defense M4 Classic Series carbines are by no means "Entry Level" firearms; they're straightforward re-creations of the select-fire counterparts used by countless military forces around the globe, down to almost every detail – quality included. This has a cost. They're not meant to be customized, although they certainly can; they have their distinct basic looks, and collectors are likely to settle for it, knowing that's what they paid for.