Rock Island Armory
STK100 9mm

Alloy Frame Stability, Hi-Cap Functionality
; .

Martin Tuason, Armscor/Rock Island’s president, is a shooter and die-hard gun-guy. He’s not one of those company presidents who used to work for an appliance company. His family started the company and the Tuason family still runs it, with Martin’s enthusiasm helping to keep the fire burning brightly.

“I wanted Armscor to get into the striker-fired market, but not with a plastic gun. That’s been done,” Martin told me. He explained Dustin Jones, their CFO, really knows the market and researched whether it’d be a good idea to make the move.

“Dustin came back encouraging us to take the leap,” explained Martin. “So, we put our heads together and decided — let’s do it.” And I’m glad they did.

Since a certain other handgun manufacturer entered the market with a polymer-framed pistol, the market exploded and now virtually all the major players offer some sort of poly-frame “wunder-nine.” The shooting public embraced the idea of a lightweight and relatively affordable design but soon found there are also a few challenges.

For one, the grip angle on many of the designs isn’t “just-right” for many shooters, requiring them to have to re-learn the feel as they adjust to pointing angles. There’s often a “point it, then adjust slightly” feel to things. Those shooters have looked longingly at their 1911s and the classic grip angle, while still wanting the higher capacity and ruggedness of the more modern designs. Enter the STK100.


Subtle Touches

Armscor/Rock Island, the world’s leading 1911 manufacturer, already knows how to build guns out of metal — they’ve been doing it for decades. So, as Martin said, “Why not craft the frame of our new gun out of metal, since it’s what we do?”

The Rock Island Armory STK100 9mm offers many of the features of a polymer
“wunder-nine” coupled with the advantages of a metal frame pistol.

Indeed, Why Not?

The result is an innovative “clamshell” frame of CNC-machined aluminum alloy with designed-in grasping surfaces and purpose-built elements, all held together with strategically placed screws. Perhaps most important of all, the grip angle is identical to that of a 1911. The additional sage notion of including a high beavertail allows a much higher grip, helping to effectively combat recoil issues. This combination of the stiffer alloy frame, innovative grip design, grip angle and the beavertail element means the STK100 sits low in the hand and handles like a Formula 1 racecar hugs the track. It’s fast to get on-target — and easy to keep there as you shoot.

A 17+1 capacity, 28 oz. weight and 7.9″ overall length places it exactly in the “duty/holster/belt carry/home defense” pistol category. While a lightweight, it’s not a pocket gun and was never intended to be, yet it fit my medium-sized hands just fine. The ergonomics allows it to be concealed easily with the right garments, holster selection and attitude. Instilling confidence, a full-sized gun is easier to handle and control, especially under stress. And, as noted trainer Clint Smith says, “It’s a big gun going into your holster — and a big gun coming back out.”


The STK100 is geared toward personal protection, offering an integral light-mounting rail.

The aluminum, clamshell beavertail grip mimics the grip angle of
the 1911 pistol for superb pointability and recoil control.

The operator controls include a safety trigger and reversible magazine release.
Also shown are the screws holding the 2-piece metal frame together.

The STK100 is both stylish and practical, with a series of lightening cuts and
molded-in grip striations in the billet-machined, parkerized carbon steel slide.

The STK100 comes from the factory with the rear sight integral with the removable optic cover plate.


Carbon steel also plays a big role in the STK100. The slide is Parkerized carbon steel and has replaceable sights. It also comes completely set-up for red dot sight installation. Now might be a good time to explain this gun didn’t re-invent the wheel when it comes to some of the basic elements, so accessories like triggers, sights and such from the likes of APEX, Lone Wolf and others geared toward the GLOCK will fit the STK100. That’s both convenient and smart as it opens a huge after-market accessory world to any STK100 owner — immediately.

The aluminum frame also adds stability to the gun that differs quite a bit from most polymer guns. Polymer guns usually have a metal insert of some sort with rails for the slide to run on. In some designs, however, the cross-pins holding action parts in place are secured through the polymer frame. When firing, the frame flexes and while this can help soften recoil it can also affect the relationship of parts. Consequently it’s not uncommon for a stock trigger on a polymer frame gun to be soft, gritty, long or otherwise not as good as you might like it to be. Check YouTube to see the slow-motion video of the process and prepare to be astounded to see the degree of frame flex possible when some poly guns are fired. Sorta’ reminds me of a horse quivering its skin to scare biting flies off.

The aluminum alloy frame of the STK100, however, keeps action parts in rigid alignment offering a more consistent trigger pull. Right out of the box the trigger on my test gun measured 4 lbs., 6 oz. with a firm consistency usually associated with metal-framed guns like 1911s, Hi-Powers and others. Keep in mind too, the many after-market action parts available will allow you to easily change the trigger system to something meeting your specific needs or expectations. Plus, the alloy frame will keep the trigger as consistent as death and taxes.

Martin told me the STK100 concept came from the need for a new issue police handgun in the Philippines, Armscor’s home country. Martin said he wanted a gun that could run 20,000 rounds and still be able to withstand the rigors of a hard life in the field. The aluminum alloy frame plays a significant role in meeting the job description.

“We essentially took the aluminum frame concept, then grew the pistol around that,” explained Martin.

I think the result is clearly a rough-duty field pistol standing up handily to anything a sport or “civilian” shooter could ever toss at it.


The stiffness of the metal frame keeps the fire controls stable, which translates into great accuracy for a production carry gun!


Shooting the STK100 didn’t deliver any surprises as much as it reinforced the fact a company’s experience manufacturing always pays dividends when introducing a new design. Applying seasoned experience on the production floor with modern engineering concepts often lands a home run, and it did here.

The STK100 was predictable on the range, delivering 1.5″ to slightly less than 2″ groups at 20 yards and would possibly do better with the right ammo dialed in. I’ve had no malfunctions of any sort, and since my article on it appeared in our sister publication American Handgunner, I’ve put another 200 or so rounds through it adding up to about 700 now. FMJ and hollow points through exotic Black Hills HoneyBadger fluted ammo ran just fine and recoil was mild, even with the hot stuff. Everyone who fired the STK100 said essentially the same thing, “I like how easy it is to shoot and it feels good in the hand.”

So there you go.


Takedown is simple and very similar to a popular polymer line of
pistols you might have heard about from Germany!

The Wrap Up

I’ve tested new guns seemingly designed by appliance engineers who formerly made washing machines. Some have been awkward, had design elements verging on the senseless, chambered in odd proprietary calibers and otherwise advertised the fact they were not invented by “gun people.” It’s like when a man designs a woman’s concealed carry purse. Really? It shows.

The STK100 shows a history of design, manufacture and support that could only originate from a company with a long history doing what they do best — making real guns for the real world.

The STK100 is, in a few words, comfortably in the top of the pack in my experience. It’s light, reliable, easy to run, ranks number one in “pointability” to me, is affordable — at $599 — and has a world of after-market accessories ready for it. And to sweeten the deal, just before we hung up from our phone call, Martin told me, “Look for new models as time passes.”

He sounded like he was grinning when he said it.

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