The Bigger Bog'

It’s been some years since Slovakian Grand Power debuted their first pistol-caliber carbine in America, the Stribog SP9A1. It was a simple blowback 9mm and considered a good value, but not a great feat of engineering.

Grand Power upped their game considerably with the 2020 release of delayed-blowback SP9A3. More than a “good value,” the SP9A3 is worthy of your nightstand. When we heard rumor of a new series of larger-caliber Stribogs, our shoulders were relieved to learn they would follow the form of the A3.

The first new offering, the SP10A3 you see here, is chambered in 10mm. From the outside it looks like a standard Stribog: 8-inch barrel, non-reciprocating charging handle, and ambidextrous controls. And, in fact, even in 10mm the SP10A3 uses a standard Stribog receiver but 2 inches longer.

It has some new features that will be seen across the entire line moving forward, along with more than a few quirks — some of these are due to the larger caliber, but most of them are thanks to the U.S. government.

What you see here on these pages is a preproduction model but representative of what’s going to be on the shelf by the time you read this piece.

10MM

Originally conceived by Jeff Cooper and actually used by the FBI, 10mm is a cartridge that has cyclically fallen in and out of favor. Now often thought of as a bear country cartridge, the reality is that it largely serves as a meme round; the number of people who say they’d buy a 10mm greatly outnumber those who actually buy a 10mm.

Still, it’s quite a powerful load, is relatively available, and excels in a subgun role. When we asked the commercial sales manager of Global Ordnance, Sam Beatty, why they went with 10mm first he told us, “… because it’s 1 millimeter better than a 9mm.” Let’s give it a look.

BRACES

We can’t talk about the government without a quick word about pistol braces. First, they were allowed, then banned, then allowed again, then banned, then determined to be stocks put on unregistered SBRs, and then, at least at the time of this writing, kind of allowed again?

Regardless of how all of this legal court business shakes out, currently the U.S. distributor for Grand Power, Global Ordnance, isn’t bundling this or any other so-called “large format pistol” with a brace. They’re still available for purchase separately, and if their use ever makes it out of the beige brown of bureaucracy, will once again be sold in that configuration.

Two different SP10A3s were used in this article, one registered SBR and the other a pistol model. The pistol has a Picatinny endcap at the rear of the receiver instead of a sliding brace or folding stock.

922R COMPLIANCE

If you’re into collecting foreign rifles, you’ve likely come across “922R” before. It refers to Title 18, Part I, Chapter 44, Section 922 of U.S. Code. It’s about the maximum number of foreign parts allowed on foreign manufactured “non-sporting” rifles.

There’s a lot to this, but what it amounts to is that if a rifle is going to have features like standard capacity detachable magazines and threaded barrels, some foreign parts will have to be replaced with domestic ones.

While this 8-inch barreled SP10A3 is technically classified as a pistol and imported like one, this isn’t the only 10mm model that’s going to be available.

In addition to pistols, there will be a 16-inch carbine version and two different SBRs: a PDW model with a sliding stock and an enhanced model with a folding stock. As those have to be 922R compliant, Grand Power and Global Ordnance decided to do all the work on their end so consumers don’t have to worry about it at all.

TRIGGER

The largest change made due to 922R was incorporating an AR-15 trigger. While the legacy Stribog trigger is clearly inspired by the AR-15 (and we can think of no better choice for a rifle), there are some clear differences, especially noticeable in the hammer. The legacy fire control group is shorter and slimmer.

The AR-15 has a lot of tight tolerances and specifications but one of the areas with more wiggle room is the height of the hammer itself. A hammer that would otherwise function just fine in an AR-15 might prevent the closing of Bog receivers.

The engineers at Grand Power moved enough around inside that GI-spec triggers work, even nice ones from LaRue and ALG, but they can’t guarantee that captive units will.

However, that isn’t the case around the board. Because this is a preproduction unit there may be some differences, but a Timney wouldn’t be a bad idea to try if you happen to already have one to test first 😉.

The ambi safety selector is still Stribog, though we were hoping for a short-throw unit. Any aftermarket Stribog selector will fit into these new lowers despite the change in the fire control unit.

MAGAZINE

While the internet-audience-at-large seemingly always cry for Glock magazines, outside of 9mm that prospect starts making less sense. There are a number of aftermarket companies manufacturing magazines for the Glock 17 and 19 but the same isn’t true for 10mm. That said, there are other 10mm guns that accept them, like the better-millimeter model of the KRISS Vector.

Another route is to base it off of HK UMP magazines like the LWRCi SMG. From both an engineering and aesthetic standpoint, this is a good idea, as they’re more reliable with higher rates of fire. The 20-round SP10A3 magazines load like a UMP magazine, first pushing each round down and then tucking back, but aren’t an exact replica of the 10mm UMP design.

The feed angle had to be modified to accommodate the AR-15 trigger group; you can click UMP mags in, but they aren’t going to run. Bummer.

The SP10A3 has two different magazine ambidextrous releases, and they work equally well. There are push buttons on either side that are easy to hit with your trigger finger, and a lever release on the back to hit with your thumb while swapping. Usually, people will find a hard preference right away and here that thumb lever really excels during swaps.

SIGHTS

The legacy Stribogs incorporated flip-up sights but here you have something different: a tiny slot-type rear sight halfway up the receiver paired with a simple post up front.

No, you aren’t likely to use them anytime soon. No, we didn’t bother testing them, either. The only reason these dinky things are included is for importation purposes; if a gun doesn’t have integral, machined sights it’s harder to bring in.

ROLLER-DELAYED ACTION

Because what Grand Power calls “Roller-Delayed” is different than HK, it deserves further explanation. There may be something a bit lost in translation here, but the Stribog does have a roller, and it causes a delay in bolt movement.

Here’s our understanding of the mechanism (see diagram on right):
There’s the forward weight, roller, and carrier. The roller sits between the forward weight and the carrier and rides in a track in the front of the receiver. There’s some linear play between the forward weight and carrier, which is where we get the delay.

(1) The recoil spring keeps the carrier forward and the roller in a low position, uncoupled from the forward weight.
(2) As the explosion of the cartridge pushes the carrier to the rear, the roller is lifted along the track.
(3) It then catches the stem of the forward weight at the top and brings it along for the ride as the spent casing is extracted.
(4) The forward weight also adds an extra reciprocal delay at the rear of the cycle, providing an extra split second for proper feeding.

It’s when cracking open the 10mm and checking out the system that the significant changes between the 9mm and 10mm A3 models are obvious. The 10mm model has a much larger bolt, but importantly the forward weight is significantly larger — despite only being a millimeter larger, the 10mm has a lot more ass behind it.

The buffer on the 10mm model is twice as thick and, on our prepro at least, is a translucent green instead of black.

OUTFITTING

Any gun that might see some real work needs sights, a light, and a sling. It was here we learned that the QD socket on our model wasn’t quite cut properly and not all swivels plugged in.

While some fit, we instead opted to attach a Magpul RSA on the Picatinny rear to clip on a single-point Tac Shield Shock Sling. Bungee single-point slings aren’t ideal in most situations, but when it comes to something like a stockless subgun they can work well. You can use it to press out for stability with the SAS stockless MP5k technique.

For a light, a SureFire X300U-A mounted in a rhino configuration is ambidextrous and helps keep everything small. The M140A Micro Scout Light Pro would be another good option here.

The optic is the new and extremely durable Promethean LP-1 from Lead & Steel. Not just a mainland China rebranding company, L&S optics are machined and assembled in the United States, and they have real engineers on staff instead of merely marketing personnel.

It’s not 100-percent made in the USA, but it’s more USA than most. The viewable window on the LP-1 is larger than an inch on each side, making it excellent for unconventional positions and imperfect cheek weld — the latter being far more important when you don’t have a stock to put your cheek on.

The reticle pattern of a 65MOA circle with a 2MOA center dot looks just like an EOTech, except that you can switch between the circle-dot, circle, and dot separately.

The Promethean LP-1 has what L&S calls “AuraWake,” which differs from other forms of shake awake in that the 2MOA dot is always on, and an internal accelerometer simply turns the power-hungry 65MOA circle on and off. With a single CR123A cell with just the center dot, L&S says the Promethean LP-1 runtime maxes out at 150,000 hours — more than a decade (and closer to two).

Of course, there’s gotta be a silencer. There aren’t terribly too many dedicated 10mm cans, but thankfully a good .45 ACP unit works just fine. At CANCON, we sent a bevy through the .46-caliber Dead Air Primal, and here we kept the Dead Air theme with a Ghost 45 in short configuration. Note that you’ll either need to purchase or fabricate a fixed barrel conversion with the Ghost 45, lest the silencer reciprocate and risk a baffle strike.

ON THE RANGE & LOOSE ROUNDS

The ammunition for testing was mostly S&B 180-grain FMJ with a smattering of 180-grain JHP from PPU thrown into the mix. As has been increasingly common with new guns, there were no stoppages or malfunctions of any kind, both suppressed and unsuppressed.

Simple blowback operation in 10mm is fairly burdensome. It makes for a gun that you like to show your friends but that you don’t like to shoot, especially if running suppressed. Just as with the 9mm A3 model, the delayed blowback on the 10mm makes a drastic difference. You can tell the recoil is heavier than the 9mm but just that little delay really evens the whole thing out.

The SBR version cleanly takes the win versus the pistol model — no surprise there. The extra point of contact greatly aids in felt recoil and control. What the pistol version lacks in usability is somewhat made up for by the ease of crossing state lines without asking for permission, but we wholeheartedly recommend to SBR it (or brace it, if the legality actually sticks this time).

The smidgin of extra handguard required for the 10mm was most appreciated in pistol form, especially as it can’t legally have a vertical grip. If this was like the A1 model with straight-blowback operation and a reciprocating charging handle, it would be far more difficult to handle.

The magazines currently being limited to 20 rounds is mildly annoying, and we hope to see higher capacities in the future. This is a gun that wouldn’t exist, at least not in this configuration, if it weren’t for the mundane meddling importation restrictions. And yet for all the trouble it caused the engineers at Grand Power, we’re never going to say no to AR-15 triggers. All newly produced Stribogs will share these features moving forward.

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