It seems an understatement to say 2014 has been a tough year for firearms industry investors. Even as the broader market flirts with new all-time highs, prominent gun manufacturers Smith & Wesson (NASDAQ:AOBC) and Sturm, Ruger (NYSE:RGR) each hover near their own respective 52-week-lows:

Stock to buy today

Sturm, Ruger & Company, Smith & Wesson Holding Corp data by YCharts

So which is the better stock to buy today? 

On one hand, Smith & Wesson is trading at a rock-bottom 8.8 times next year's expected earnings and just 0.87 times trailing 12-month sales. And despite its more pronounced share price decline, Ruger looks slightly more expensive with a forward P/E ratio of 12.9 and trading around 1.22 times last year's sales. On the other hand, that could also reflect the fact Ruger is operating with no debt and $28.1 million in cash on its balance sheet. Smith & Wesson's books are decidedly less pretty, with around $83.5 million in cash and $175 million in long-term debt in the form of unsecured notes.

A tale of two (mostly) similar quarters
It also helps to explore what brought us to this point.

Three weeks ago, Ruger's third-quarter results badly missed expectations on both the top and bottom line. Ruger CEO Michael Fifer's reasons were varied, but he primarily blamed the underperformance on a combination of falling consumer demand (down 3% year over year based on the latest NICS background checks) and high inventory levels. All told, Ruger saw sell-through from independent distributors to retail decline 44% year-over-year as they worked to reduce inventory and generate cash.

If that sounds familiar, it's because Smith & Wesson CEO James Debney said almost the same thing in late-August following his company's own fiscal first-quarter whiff. For perspective, note that the end of Smith & Wesson's fiscal Q1 overlapped the beginning of Ruger's Q3 by roughly a month.

One key difference
But make no mistake; there is one crucial difference between Smith & Wesson and Sturm, Ruger right now: market share. More specifically, the market share Smith & Wesson appears to be taking from Ruger.

Normally when Smith & Wesson reports each quarter, it compares domestic unit sales to NICS background checks as a gauge of whether it's taking market share from competitors. Back in June, for example, Smith & Wesson gained market share as domestic unit sales jumped 9% year over year, while NICS background checks simultaneously fell over 20%. Last time around, however, Smith & Wesson stated that those high inventories and "noise in the channel" made the comparison a less reliable measure. Instead, they opted to more vaguely note that their own monthly analysis showed that Smith & Wesson was still the "market leader" in both handguns and modern sporting rifles.

However, this wasn't confirmed until Ruger's most recent report. In addition to high inventories and falling consumer demand, Ruger admitted that it probably "lost market share" as a result of its decision not to match aggressive price discounts implemented by many of its competitors.

I'm not a betting man, but I'd be amazed if Smith & Wesson wasn't a primary recipient of that market share.

Follow that market share
On the flip side, that would also mean Smith & Wesson is guilty of the aforementioned "aggressive price discounts," which could mean it consciously chose to sacrifice margins in the name of growing -- or at least maintaining -- its top line.

But we should also keep in mind that when Smith & Wesson last reported in August, it drastically lowered its outlook for earnings and revenue for both the current quarter and full-year 2014. At the same time, Smith & Wesson management said those stubbornly high inventories were expected to taper off in the coming quarters as the market returns to a more normalized environment -- a sentiment Ruger management incidentally also echoed only a few weeks ago. With Smith & Wesson's expectations already reduced, I can't help wondering whether we'll hear a decidedly more positive tone during the company's impending quarterly report next week.

To be clear, it speaks volumes that both companies are still profitable even in this difficult environment, so I'm not giving up on either of them as prospective long-term investments. But if I had to choose which stock to buy today, I would follow the market share to Smith & Wesson.