Rather than use gas to blow back the bolt carrier, like the M-16 does, the AR-180 uses an operating rod that drives the bolt back without introducing gas into the receiver. Less gas in the receiver means a cleaner weapon.
Unfortunately for ArmaLite, the M-16 was just too firmly entrenched with the U.S. military to be displaced by the new upstart, even though it was cheaper to produce and possessed the same level of accuracy. The AR-180 was marketed to civilian consumers.
ArmaLite ran into difficult financial straits in the 1980s and was sold. It changed hands a couple of times after that, but ArmaLite never manufactured another rifle until Westrom resurrected the company in 1995.
The New AR-180
Shooters will immediately notice just how light the new AR-180B is. It weighs just 6 pounds.
Most of the weight savings comes from the innovative new polymer lower receiver. "We decided to go to a polymer receiver for strength," says Westrom. "The old sheet metal AR-180s were notorious for cracking at the welds but you can take one of these plastic receivers and fling it against the concrete floor without cracking it. Polymer yields and reduces stress more so than steel or aluminum. Additionally, the plastic is corrosion proof, costs less to manufacture, and saves about a pound of weight per rifle."
Of course, you can have a lightweight rifle that feels "heavy" because its design yields poor balance. The AR-180B does not have this problem. It feels "light," and it balances just forward of the magazine well. It's not muzzle or butt heavy.
Quality manufacturing is evident throughout the AR-180B. ArmaLite's polymer lower receiver does not display any obvious casting imperfections and the seam between its halves is barely perceptible. Its grayish color also matches the color of the sheet metal upper well.
To reinforce the pin holes, ArmaLite uses steel plates internally on both sides of the receiver. There's no chance that extended firing will cause the pin holes to egg out of shape.
New and Improved
The new AR-180B has a fixed stock that does not fold like the stock on the original AR-180, though it does match it in profile. With the recent expiration of the 1994 Assault Weapons Ban, the folding stock may once again become available on the AR-180B.
Like the original AR-180, the new AR-180B has no external bolt lock. If you'd like to lock the bolt open there are two ways to do it. The easiest way is to lock an unloaded magazine into place and pull the bolt handle rearward. That will lock the bolt to the rear, and the magazine can then be removed. The other way is to stick a finger up into the magazine well and push the internal bolt lock into position while pulling back on the bolt handle. It's not as awkward as it sounds and becomes second nature after a couple outings with the rifle.