7075-T6 aluminum has had a pretty good run as the materiel of choice for AR lower receivers, but it’s no longer the only game in town. Taking advantage of the lower weight and manufacturing costs of space-age polymers, New Frontier Armory sells an all-polymer AR-15 lower receiver with a price so low ($109 complete) that even cautious shooters are reaching for their wallets and asking themselves, “Why the hell not?” And why the hell not? Your financial exposure is pretty small if a $109 purchase doesn’t work out, but the real question is “Does the damned thing work?” Even the lowest-priced gun has very little value if it’s unsafe or unreliable . . .