Rock Island Armory's STK100

9mm Defense — Re-Engineered!

I was chatting with Martin Tuason, Armscor/Rock Island’s president on the phone about their new STK100. It was obvious he was enthusiastic about the new gun.

“I wanted Armscor to get into the striker-fired market, but not with a plastic gun. That’s been done. Dustin Jones, our CFO, knows the market and did the research. He came back encouraging us to take the leap. We put our heads together and decided, let’s do it.”

Martin went on, “And, since we’re famous for working with metal it was only natural we decided to do what we do best. We’re the number one producer of metal 1911s in the world so we know how to do it!”

So they did.

As I talked with Martin I was holding their brand new STK100 in my hand. I had shot it some to get familiar with it before calling him, and it had run just fine. I’d call it “fun to shoot” even. Think “modern defensive pistol” like we’ve grown familiar with — but with some key differences.

The STK100 is 17+1, 28 oz. and about 7.9″ overall. Call it a full-sized holster pistol if you would. The slide is carbon steel (Parkerized), having easily replaceable sights. The slide is also supplied fully machined with a red dot sight cut-out. To me, one of the most powerful features is the all-aluminum frame with machined-in integral grips. There’s also a high-cut beavertail allowing a very high, secure grip. I have medium-sized hands and can reach the trigger comfortably in spite of the double stack magazine girth. It’s obvious some thought went into the grip assembly.

But praise be, at his insistence, Martin’s team changed the grip angle to match that of a classic 1911. When you pick up the STK100 and point it you notice the difference immediately. There’s no “point, then adjust a tad” going on. You bring it up and it locks right in — presto. If you don’t think this matters lay gun “B” on the gun store counter, and place the STK100 next to it and pick them up one after the other. I promise you’ll grin and say, “Oh, I get it now.”

Action parts are a mouse click away. The clamshell frame makes installation
easy since the frame halves come completely apart.

Replacement or custom sights are available from a wide range of after-market shops.
The slide comes pre-cut and fitted for a red dot sight.


Armscor is truly a family-owned business and the people who run it are gun-people. They shoot, talk guns and are working constantly with their customers, military and police to keep honing products and creating new ones.

The STK100 comes from a police gun concept in the Philippines where the company originated. Martin wanted something that’d run 20,000 rounds and be able to withstand the rigors of hard use in the field. He felt the aluminum frame made good sense as part of that idea.

The result is a unique two-part “clamshell” frame. If you look at the photos, you can see small screw holes along the frame’s perimeter. Lurking just inside the holes are Allen-headed stainless steel screws. This combination of aluminum and assembly engineering allows a few interesting things to occur.

To get to the action bits it’s easy to simply take the gun apart. Now you can see and handle everything inside clearly. Also, this assembly method allows much easier machining of the frame as both “sides” can be done next to each other with no need to dig deep into a blind hole, for instance. Deburring, drilling, etc. can go smoothly — and faster. This keeps costs down too, allowing a lower MSRP.

I think the most important thing about the aluminum frame is the fact it adds rigidity and repeatability. Cross pins, screws and assemblies inside tend to ride smoothly. The relationship of parts like sears and action bits remain fixed to one another. No (or extremely little) frame flex means a more reliable trigger pull and long-term predictable dependability.

The Rock Island STK100 may look like it has a polymer frame, but it doesn’t. Rock Island
felt aluminum yielded a better result and Roy thinks they’re right.

If you look carefully you’ll notice the grip angle isn’t the classic “Polymer Pistol” one. The STK100 matches the classic feel of the 1911, improving pointability significantly.

A Base Gun?

Custom parts from the likes of Lone Wolff Distributors, ZEV, Technologies, APEX Tactical and others fit.

As Martin said, “Why re-invent the entire wheel when it’s only a few important segments that could stand to be upgraded, like the metal frame, for instance?”

There’s a world of after-market parts available for popular guns like the Ruger 10/22, AR-style rifles, GLOCKs, etc. and Armscor is riding the wave with the STK100. Sights, triggers, barrels, magazines, etc. are all potential drop-in accessories already on the market ready to go into an STK100. And, at about $595 at full MSRP, it’s a good way to get into the “custom gun” fun trend building your own idea of what a “perfect” defensible pistol would be to meet your needs.

The STK100 design borrows features from another famous model — but with
some significant changes like the aluminum clamshell frame!


The grip angle makes such a difference as to be immediately noticeable. General gun-handling seems a bit smoother for me, and bringing the gun up to shoot feels as if the sights settle right where they belong. I found it to be fast, secure and certain when pointing.

The grip texture machined into the STK100’s frame surface is contoured the way it is for a reason. The front strap horizontal cuts help to keep the grip from moving vertically when firing. The rear angled cuts help to keep the back-strap from rolling up and right under recoil (if you’re a right-hander). The side checkering gives your palm and fingertips purchase to hold their places properly. Combined they act as a sort of triple threat to the gun moving under recoil.

Shooting was, in short, a delight. I’m no newcomer to all this and I’ve literally shot hundreds of this style of handgun over the years. From the earliest “high cap” autos in the middle 1980s as a cop, to today’s most cutting edge designs, I’ve got tens of thousands of rounds through them. With that much exposure you can’t but help develop a sort of automatic response when hand-ling them. “Oh, this feels like I thought it would,” you seem to say to yourself. It’s easy to become complacent unless you’re surprised suddenly.
Which I was.

The STK100 isn’t another clone of a clone of a clone — but pushes the envelope out even further.

That’s 1.5" at 20 yards from a rest using Armscor 124-grain ball ammo. Roy found the STK100 to be reliable and very accurate.

On Target

Trigger pull averaged about 4 lbs., 6 oz. and reset was secure and audible. I liked that. It also smoothed out as I shot the gun. But I’ll be honest and say I’d look forward to a crisp APEX style trigger some day as they tend to spoil you terribly. The STK100’s aluminum frame would also mean the aftermarket trigger would remain sound as time passes with no surprises.

The sights were fine, with a white dot front and, combined with the comfortable grip angle and ergonomics, showed me this gun can shoot. The STK100 gave me dependable 5-shot groups in the 1.5″ to 1.75″ range at 20 yards using Armscor 124-grain FMJ ammo. That’s a stock $600 gun, stock trigger, stock barrel, stock sights, etc. I can only wonder what we could accomplish with a custom barrel, trigger and sights.

I’ve got just short of 500 stashed rounds through it. I cleaned and lubed it when I got it and it’s run just fine since. It’s a very early pre-production gun and to be frank, they often suffer from glitches. But this one runs great, which bodes well for production models. Since they have it sorted out this early, the rest will be easy.

In short, this gun is not only fun to shoot, but it’s manufactured by “gun people” — and they nailed it. Martin, the ever-present, ever-vigilant company president said to “Look for new models as time passes.” It’ll be interesting to see what they come up with.
And remember — dogs can’t eat an STK100. Just sayin’.

For more info:, [email protected]

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