Poly Receivers Part 3: Bench Comparison

John over at TN Arms casually reminded me recently that I still hadn’t done the side by side comparison I promised to do a while back between their receivers and the New Frontier LW-15 I have on hand.  Don’t worry, I haven’t been too discouraged by my inability to destroy my test lower but I did get temporarily sidetracked by the Turkish Invasion and have been working on range reviews for those Canik pistols plus the Dagger muzzle brake!

Spec Sheet

Here are the general specs on both receivers for reference…

TN Arms

  • Retail Price: $149 w/metal LPK, stock (mil-spec) and grip OR $37-60 stripped
  • Material: Nylon 6-6 blend with brass inserts
  • Weight: 5.4 oz
  • Colors: Black, Clear, FDE, Coyote, Foliage, OD Green, Pink
  • Notes: Includes shortened grip screw, oversize trigger guard

New Frontier LW-15

  • Retail Price: $119 w/poly LPK, stock and grip (commercial spec)
  • Material: Unspecified nylon blend
  • Weight: 5.0 oz (stripped)
  • Colors: Black
  • Notes: Reversible safety lever (polymer)

Manufacture and Material Quality

Both receivers side by side

Both receivers side by side, yes I was too lazy to remove the bolt stop

Though I don’t have any real specs on the New Frontier polymer mixture, it’s apparent even with my shoddy camera work that the two receivers use significantly different materials.  While both seem fairly sturdy, the New Frontier feels more like a Glock or M&P frame while the TN Arms material feels more like a rigid synthetic rifle stock.  Material wise both are quite sturdy and only have minimal flex in the thinnest portions at the very worst.

I am by no means an expert on polymers or injection molding processes, but looking over both models of receiver it’s easy to see that both companies use different methods to achieve similar ends.  The TN Arms receivers have final fitting and machining work done on them, which is much more obvious on earlier generations before most of the quirks were ironed out.  On one hand it’s nice to know there’s some work put into them by actual humans, but if you’re the type that cringes at small cosmetic defects and swears off blem model receivers you might be bothered by that.  Most of the areas machined out or fitted down are hidden by various components anyway.

On the flip side, the New Frontier unit looks like it came right off the mold with some flash trimming at the worst.  The face of the buffer tower is sanded flat, but aside from that there are scant few signs of fitting or work done after the molding process.  New Frontier advertises that their receivers have exceptionally tight fit, which sounds to me like marketing speak for “we left everything a tiny bit oversized”.  As long as it works I can’t complain, and the fit and function of this early LW-15 is just fine.

Design Differences

Here’s where things get way more interesting!  A whole lot of polymer receivers over the years have used similar molds or have been based off of the same mold, to varying degrees of success.  It’s ungodly expensive to have a mold machined, so it’s not really a surprise that much of the focus on poly receiver development has been in materials.  At a glance, it looks to me like the New Frontier unit is very similar to many of the existing polymer receivers from around the time they hit the market.

TN Arms' brass inserts compared to the LW-15

TN Arms’ brass inserts compared to the LW-15

TN Arms’ claim to fame is the use of molded in brass in two key spots: the buffer tube threads and the pistol grip threads.  That’s the first and most obvious design difference, but looking at the above picture you’ll also see that the buffer tube area is significantly reinforced to the point it’s about the same shape as the endplate itself.  Material has been added in several critical spots where most other poly receivers fail epically including the biggest culprit of them all: the rear takedown pin.  Inside the rear of the fire control pocket there’s some extra material where the New Frontier receiver is hollow providing some more support.

In non-critical areas TN Arms took a few liberties as well.  The lower has a full fence unlike most polymer receivers I’ve encountered which use a small C shaped partial fence, providing a much more mil-spec look.  The magwell is flared more aggressively and as a side effect is more rigid than the LW-15 here.  The TN Arms unit has more prominent selector stops and duplicates the stops and fire control markings on the right side of the gun, which the LW-15 sadly dispensed with for some reason.  As mentioned above the TN Arms receiver has an oversize trigger guard which is a nice addition, especially since I absolutely hate flat trigger guards.  One final little note is that the added material around the buffer tube threads allow for threading the detent hole to use a setscrew retainer which I have done on the pictured receiver.

The magwell and front takedown pin areas on both

The magwell and front takedown pin areas on both


The main reason this side by side review keeps slipping on the schedule is because the results of my torture tests on the TN Arms receiver coupled with the price point, customer service and availability as a stripped lower really make it a no-brainer.  They’re tough as nails, and I wouldn’t trust the New Frontier receiver to survive the tree test.  That doesn’t mean New Frontier has a bad product by any stretch, but I’d certainly consider it to be a “medium duty” receiver somewhere between fragile .22-only lowers and aluminum receivers.

As always, feel free to shoot me any questions via email.  I hope to continue some torture testing on the TN Arms as time goes on, so feel free to suggest tests too!

Parting shot: here’s the current FDE test lower with a couple small additions.