Gun Review: New Frontier Armory LW-15 (Polymer AR Lower Receiver)

Just another entry-level AR lower? Not quite.

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 . . .

To get this test sample, I ordered one through the New Frontier Armory website. I didn’t mention TTAG and I didn’t ask for a T&E sample; I just ordered one off the shelf like any other customer. That’s how I learned firsthand that New Frontier’s front-end customer service is freakishly good: they answered my email questions within 10 minutes (on a Sunday!) and they shipped the receiver out the next morning. I did the Form 4473 Shuffle and picked up the all-plastic lower from my gunsmith seven business days later.

How plastic is ‘All Plastic?’

The LW-15 is basically all plastic. The buffer parts, bolt catch, action springs and pistol grip screw are metal, but everything else is made of polymer. Even the mag catch, trigger, hammer, safety and takedown pins are made of some tough, hard plastic.

The body of the receiver is made from an extremely rigid glass-filled plastic. The design is externally similar (read: almost identical) to the Plum Crazy polymer lowers we’ve seen for a few years, but New Frontier uses a different polymer formula and different reinforcing fibers. If you like to watch gun porn of the ‘snuff’ variety, New Frontier has some brutal testing videos on its website.

Fit And Finish

At least there’s no ‘gap’ behind the trigger guard.

It only takes a moment to notice that this is very much an ‘entry-level’ AR lower. You’ll never mistake an LW-15 for an LWRC. The exterior looks mostly well-executed, but some bits look a little rough and others just look like crap. There’s molding flash at some of the seams, but this is only a cosmetic issue except for the burrs on the single-stage trigger face. These are polished away easily enough, but the underside of the trigger guard and the space between the front takedown pin holes are fugly. Once again, they’re nothing a few minutes with an emery cloth won’t remedy, but they’re still ugly.

The good news is that this slightly rough external finish has no effect on fit or functioning, and no effect on how the lower half attaches to an upper receiver. Our test lower mounted very tightly to my Armalite upper; there was absolutely no wiggle or wobble anywhere. It’s a much better fit than my off-brand forged aluminum lower, which wiggles a little bit even with an ‘accu-plug’ crammed under the rear takedown pin.


The all-plastic fire control group functioned flawlessly.

Regardless of its unorthodox construction, the LW-15 operates exactly like any other AR lower. The all-plastic single-stage trigger is an unexpectedly pleasant surprise: it’s kind of hard to describe a trigger pull scientifically (at least until Foghorn actually builds the computerized graphing trigger gauge he theorized about) but the LW-15’s trigger pull is very smooth, not too heavy (5.2 pounds) and fairly short with minimal overtravel.

It’s also a little mushy/spongy/vague (take your pick) but it’s one of the best triggers I’ve seen included with a lower-priced AR. I wish it were lighter by a pound or so, but it still helped deliver some amazing accuracy.

The selector lever has a smooth and positive feel, and it would only be better if it were ambidextrous. I like that the LW-15 is ready-made for an ambi lever: it has ‘SAFE/FIRE’ markings on both sides of the receiver.

When it came to magazines, the LW-15 was like Mr. Creosote: it ate everything we put on the table. (No ‘wafer-thin mints’ here.) My Magpul P-Mags, Joe’s steel magazines from H&K, and Wayne’s GI magazines all snapped home neatly, fed perfectly and dropped free when released.


Firing and functioning of the LW-15 lower receiver was absolutely reliable, through more than 500 rounds. The all-plastic trigger and odd-looking hammer provided 100% ignition with everything we gave it: Remington Green Box, steel-cased Tulammo, Radway green tip and whatever other mil-surp ammo Joe Grine had rattling around in his range bag. It worked with FMJs and hollowpoints, brass cases and steel, in fair weather and heavy snow, through slow fire and mag dumps. It just plain works.


An AR is only as accurate as the sloppiest of its components, even though the upper half plays a more important role than the lower half. I bolted the LW-15 to a mid-length Armalite upper with a full-profile barrel and proven accuracy. Shooting prone in the snow from 80 yards (Note to self: measure twice, set up firing line once) it averaged under 1.0″ with Remington Green Box, and that doesn’t even include a varmint-worthy 0.25″ cloverleaf. I kicked myself for not measuring out a full 100 yards, but these groups still demonstrate that the LW-15 didn’t let us down when it came to accuracy.

Conclusion: The Good

The magazine well is slightly more flared than that of most forged AR lowers.

The first and most obviously cool thing about the LW-15 lower is that it’s ‘Sofa King’ cheap that it’s hard to pass up. For $109 it’s already got a functional M4 buttstock and all the moving bits you’ll need; all you have to do is pin it to an upper half and start loading up your magazines. Even after shipping, taxes and FFL fees, it will still set you back less than $150.

The second cool thing about the LW-15 is that it’s incredibly light. The fully kitted-out LW-15 lower half tips the scales at 1.7 pounds, which is a half-pound lighter than a forged lower half with same buttstock. If you choose your components wisely, you’ll use it to build a dedicated .22 carbine or a stripped-down 5.56 carbine weighing between 5.5 and 6 pounds. Whatever you do, keep it simple and keep it light: a varmint-barrel upper (or any tactical tomfoolery hanging from your handguards) will give you a muzzle-heavy blunderbuss with the handling alacrity of a Marlin Super Goose Gun. (Remember those?)

I was surprised at how gently (for lack of a better word) this very lightweight receiver shot and cycled. Perhaps it’s a serendipitous combination of barrel and buffer harmonics. Or perhaps, as is the case with polymer-framed pistols, a slight flexion of the lower receiver acts to mitigate the already-mild 5.56mm recoil.  However it works, it shot slightly smoother than a forged AR lower with a fixed A2 buttstock.

The LW-15’s trigger pull, tight lockup, and exceptional accuracy were all unexpected at this price point. In fact, these features would be gratifying even on ARs costing $1,000. In many regards, the LW-15 is superior (so far) to many entry-level forged AR lowers I’ve dealt with, while costing less than half what they cost.

With careful shopping, the LW-15 will let you build a six-pound AR for less than six bills.


One of several purely cosmetic blemishes.

If you want to build a drop-dead gorgeous race gun, you WILL NOT start with an LW-15 if you’ve actually looked at all my photos. In addition to its numerous cosmetic flaws (and questions from your competitors like: “You’re running a what?”) it’s just so damned light that you probably won’t want to hang any tactical doodads from it. Quad-rails and bipods are a no-no: too much weight at the muzzle or fore-end will make it handle like crap. As Sean Connery’s Ramirez told the young Highlander Connor MacLeod, balance is the secret to nearly everything.

Although the LW-15 is ‘mil-spec’ in most of its dimensions, it’s not 100% compatible with other mil-spec parts and accessories. The integral trigger guard works fine but it can’t be removed or replaced unless you’re really handy with a Dremel tool. The buffer tube, for no discernible reason, is commercial diameter instead of mil-spec. It can be replaced with a mil-spec tube, but I would be very cautious not to over-torque the castle nut when doing so.

The LW-15 will accept any mil-spec trigger group, with two exceptions: drop-in units like Timney triggers won’t fit, and if you do swap out the trigger parts you’ll have to replace the selector/safety switch also. The included selector only works with the LW-15’s plastic trigger group.

Multi-Caliber Options

Every LW-15 lower is designated “CAL.MULTI.” Most of them will eventually wear a 5.56 upper, but many other cartridges can cycle through a standard AR-15 action. A .22 long rifle upper is an obvious choice, but is this polymer lower receiver a good choice if you’re looking for a cartridge with a little more horsepower than the 5.56?

New Frontier advertises that they’ve tested the LW-15 for safety and durability with heavy-caliber upper receivers like the .450 Bushmaster. The LW-15 is apparently safe and reliable with a .450, but I don’t know how many rounds they ran through it.

I also haven’t seen any rigorous independent testing in calibers other than 5.56, so I would counsel caution with this relatively new receiver technology. The LW-15 is more than adequate for Foghorn’s darling .300 AAC cartridge, because it has a pressure and recoil profile that’s similar to the 5.56. One regular on has been happy with a .458 SOCOM upper on his LW-15, but if I had a sledgehammer like that (or a .50 Beowulf, or a high-pressure caliber like 6.5 Grendel or 6.8 SPC) I think I’d hang back and let someone else to test it on their polymer lower first.

How Do You Clean It?

Plastics don’t always like solvents, but the LW-15 proved completely safe to clean with Hoppe’s No.9, Break-Free CLP and M-Pro 7 gun cleaners. In lieu of wiping it with drain cleaner or battery acid, I diligently searched the Interwebs for information on how to ruin it with harsh solvents. And it was all for naught: the gun forums are full of questions about solvent resistance, but nobody has actually seen an LW-15 that was damaged by gun cleaning chemicals. FWIW, New Frontier claims that it cannot be harmed by any common gun cleaners.

Ignoramus et Ignorabimus

The only really dark cloud hanging over the LW-15 is its unknowable long-term durability. These plastic lowers just haven’t been on the market long enough for Early Adopters (like us) to test them with thousands and thousands of rounds.

Five hundred flawless rounds (and counting) is the perfect way to start demonstrating quality and reliability. That’s a great record for reliability: my TTAG testing career has only introduced me to three other outstanding firearms (an FN, an Arsenal AK, and a SIG/Sauer) that were as reliable out of the box. 500 rounds is good, but I’ll keep testing this receiver because when you shoot your 5.56 ammo by the case you’ll learn the crucial difference between reliability and durability.

The LW-15 receiver (right) has a tighter fit, and possibly better accuracy.

Since durability will be the key to whether the LW-15 is a good value or not, I’m going to treat this as a the first installment of a long-term review; I’ll check back next summer with an update on the LW-15’s round count and malfunction log.

If I had to guess where the LW-15 might fail early, it might be the plastic takedown pins, the buffer ring or the front takedown pin holes.

Warning: firearms were harmed in the making of this video. Scroll to 2:12 to see dirt literally spraying out of the barrel. Heaven knows I’ll never do that to my firearms, but it’s nice to know the LW-15 doesn’t have a glass jaw.

If you search for ‘new frontier armory polymer failure’ you’ll quickly find the same few failure anecdotes I did, but you’ll also find that New Frontier Armory took care of the owners and sent them new lowers. There doesn’t seem to be any solid body of evidence suggesting that the LW-15 is any less reliable or durable than a forged aluminum lower. Only thousands of rounds will tell if this polymer lower will hold up as well as they  do.

At this point I can definitely say that the LW-15 looks completely solid so far, and I’ll sound the alarm if it doesn’t hold up.


The LW-15 looks like a good entry-level lower, and for $109 it’s a flat-out unbelievable value. Reliability has been impeccable so far, but long-term durability has yet to be proven.

RATINGS (out of five stars):

Fit and Finish **1/2
Tight and sturdy but rough at the edges. Still better than you’d expect for $109.

Ergonomics ***1/2
Don’t let those rough edges fool you: it’s got a good trigger and smooth, positive controls.

Reliability **** (and counting)
Perfect so far, but subtract a star for unknown long-term durability.

Overall ***1/2
A fantastic value at $109, although I wouldn’t take it to war just yet.