Mating to the front of the receiver is a quick-change barrel assembly. The system consists of an interrupted Acme-type thread and a spring-loaded detent. The design is intended to allow a rifleman to swap out barrels, no tools required, in a matter of a couple of minutes, so a rifleman can swap from a 101?2-inch shorty to an 18-inch DMR tube and back, no wrenches, no fuss.

Better still, the system is built around modified AR-15 barrels to ensure a plentiful supply. In addition, the barrel is freefloated to enhance accuracy.

Mounted above the barrel is an AR-180-type piston assembly. This removes as one unit but can be easily stripped for cleaning. Regulating the flow of gas to the piston is a three-position gas regulator. A rifleman can select "S" for use with a suppressor, "R" for normal conditions and "H" for extreme cold or when the weapon is very dirty. The basis for this simple system has been in use on military weapons since at least the 1930s and is well proven.

The upper is crosspinned onto a lower receiver manufactured from long-strand fiber-reinforced impact-modified polymer. This features fully ambidextrous controls, which are very nicely laid out. Housed inside, one finds a drop-in trigger pack that utilizes standard AR-15 components.

One interesting feature is the option of using standard M16 or AK magazines through the use of dedicated lower receivers. This allows a rifleman to easily reconfigure the rifle to feed 5.45x39mm or 7.62x39mm ammunition from standard Com Bloc magazines. Since the upper, not the lower, is serialized, there is no hassle with buying an additional lower either.

SPECIFICATIONS Masada Adaptive Combat Weapon System
MANUFACTURER:	MagPul Industries
FEED:	Standard AR or AK mags, depending upon lower receiver
CALIBER:	5.56 Standard
OPERATION:	Short-stroke gas with rotating bolt
BARREL:	Quick-change system using modified AR barrels
CONTROLS:	Fully ambidextrous
WEIGHT:	6.7 pounds with 14 1/2 -inch carbine barrel
STOCK:	Folding, standard and precision stocks available
LENGTH OF PULL:	Adjustable
PRICE:	$1,400

To increase the versatility of the design, the lower receiver is designed to allow easy tool-less changing of the buttstock. Currently, MagPul plans on offering three different stocks: folding, standard and precision rifle. The folding stock not only folds to the right side of the weapon but also telescopes to adjust length of pull. The standard stock does not fold, is more robust and features an increased range of adjustment. Both of these stocks also feature an adjustable cheek riser for use with optics. The third stock is intended for use on Designated Marksman rifles and is similar to MagPul's well-received Precision Rifle stock. This unit features an adjustable cheekpiece and buttplate. All the stocks feature mounting points for QD sling swivels.

Multiple easily changed handguards are also offered in both polymer and aluminum alloy. The polymer handguards are designed to accept bolt-on 1913 rails to allow a rifleman to configure his weapon to meet his specific needs. Basically, you have the option of only mounting the rails you actually need. The aluminum fore-end, on the other hand, features full-length rails.

In addition, a folding front sight is mounted to the weapon and a full-length 1913 rail runs along the top for mounting day or night optics and backup rear sights. Plus, storage space is provided in water-tight compartments in the butt and pistol grip. Weight of a 14 1/2-inch carbine model is only 6.7 pounds.

Although the Masada is at this point only in prototype form, I think it holds a lot of promise. In the hands, the weapon feels fantastic, and the controls all fall easily within reach. From what I have seen so far I am very impressed by what MagPul put together in just four months of midnight oil.

Time frame for release? Don't expect to see a production Masada until 2008, so don't bother calling the company right now. This was just intended to be a first look at an exciting new rifle in the works.

Price? It's projected to be right around $1,400.

As it's still in prototype form, how the design evolves and actually works remains to be seen. However, whether the Masada is a success or a failure, the fighting-rifle bar has suddenly been raised by the features brought together in this user-friendly design.