I have been watching the development of several versions of polymer lowers over the past few years, and after learning more about their product development and testing process I decided to try out New Frontier Armory’s polymer AR-15 lower (LW-15 Gen II). While many AR-15 owners are still hesitant to trust a ‘plastic’ lower, there is a world of difference between cheap plastics found in poor-quality products and the advanced polymers used in pistol frames and these lower receivers. Just as it took time for soldiers to accept the idea of the ‘plastic’ M16 and the ‘plastic’ Magpul PMags, it will take time and experience to proove the worth of polymer lowers.

One of the key benefits of polymers is that they retain their shape and size better in extreme cold and yes, heat (unless you are the human torch, why do you care that your Glock would melt if cooked at 450 degrees?), and they also spring back to their original shape after bending or twisting far better than steel or aluminum. They also can flex further without shearing, making them an ideal composition material for a pistol frame or AR-15 lower receiver. 90% of the stress from recoil in an AR-15 is absorbed in the barrel, barrel extension and bolt lugs, the barrel nut itself doesn’t see a great deal of stress for that matter.

Their pricing for a complete lower receiver with a 6-position stock is incredibly low ($109.99 shipped currently), if nothing else it was a cheap opportunity to try something different. While they are extremely light compared to aluminum lowers, the quality of the lower is very good. They have reinforced key areas with thicker polymer material and support ribs, and after viewing some of their torture tests it’s hard to argue that they aren’t tough enough for regular use. The polymer lower parts kit is also very hardy, their action-proving test cycled the hammer and trigger thousands of times at extreme speed without any failures. If the polymer parts are not to your liking, they are interchangeable with any standard lower parts kit.

So far with several magazines through the LW-15 lower with various ammunition and upper receivers (including M4-style carbine uppers and a mid-length upper with a free-float rail) the LW-15 has been flawless so far. The trigger is smooth and consistent, with a very short, crisp reset (approximately 3/16″). It’s rare that a stock trigger is smooth and crisp enough that you don’t notice it, even when paying attention to the details, but this trigger will hold it’s own against any mil-spec trigger group I’ve tried. The balance of the rifle with this lower is very good, I thought it might be front heavy, but it feels much more balanced than an aluminum lower with the same upper receiver and stock configuration.

Time will tell how well this lower holds up to repeated use, but from what I can see so far New Frontier Armory has done an excellent job learning not only from their own testing, but the failure points of other designs.

By: Joel Gilbert

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Tactical Gun Review, along with Texas Outdoors Network, is published by Michael Coker and Charles Coker.

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