Design Concept
In recent years, pistol caliber sub-guns have taken a back seat to small platforms that are chambered for rifle calibers. This shift is due to the power increase from rifle calibers making smaller chamberings like 9mm less attractive. The Stribog SP10A3 helps bridge the gap, offering the 10mm pistol caliber, which packs a major punch over calibers like the 9mm.
To put it in perspective, a traditional 9mm loading is a 115-grain bullet with a muzzle velocity of about 1,250 fps in an 8-inch barrel. This translates to just shy of 400 foot-pounds of energy transferred on target. In the same 8-inch barrel, the standard 180-grain 10mm cartridge is coming at at just shy of 1,500 fps. This translates to 875 foot-pounds of energy transfer, more than double the 9mm.
Needless to say, this cartridge packs a punch.
Features
The SP10A3 is a roller-delayed design modeled after the SP9A3. It feeds from polymer 20-round magazines and has familiar controls. The safety is accessible by the right-hand thumb, and the platform has a left-mounted bolt hold/release akin to the placement on an AR platform.
The magazine release is ambidextrous, with a flapper or push-button release. The charging handle is non reciprocating and can be placed on either side of the firearm.
We’re featuring the SP10A3 in a Guns.com tacpack that includes an SB Tactical folding brace, a SIG Romeo 5 Gen II red dot, and an Arisaka Defense hand stop. This package also includes three 20-round magazines.
On the Range
As someone who has fallen victim to replacing my 9mm sub guns with rifle caliber designs, it was a real treat to get to shoot a platform that packs a punch like the SP10A3. There is something special about the compact nature and aesthetic of a pistol caliber sub-gun. Ever since I learned about the 10mm and .40 S&W conversions for the MP5, I have wondered why more companies did not pursue those calibers.
The 10mm round shoots like a dream out of the SP10A3. I expected to feel a major difference between shooting a 9mm and 10mm, considering the major shift in power coefficient. In reality, I would say the difference in recoil is negligible. With a smooth push into the shoulder, the roller-delayed action makes it easy to get quick follow-up shots and watch the dot return to the target quickly.
I shot around 500 rounds with a mix of FMJ and JHP ammunition, without a single malfunction. At about 25 yards, I shot a nice five-round grouping with almost every hole touching, giving me great confidence in the practical accuracy of the platform.
Shooting Notes
The 8-inch barrel is easy to maneuver and quick to transition from target to target. It’s threaded with a .578x28 pitch, like most .45 ACP barrels. I threw on a Banish 45 and was impressed by the sound and recoil reduction with the fast and powerful 10mm cartridge. Plus, the platform is still compact with a suppressor.
Related Review: Light and Quiet, the Banish 45 Suppressor Puts Any Handgun Into Stealth Mode
While the original SP9A3 had some issues with the straight magazines, the SP10A3 does not, as the 10mm cartridge is optimized for a straight-wall magazine. I normally have to oil my SP9A3 magazines, but I had perfect reliability with these 20-round 10mm magazines out of the box.
I would argue the addition of a red dot is essential for the platform. While there is a tiny front post, you won’t achieve practical accuracy without an optic. The Arisaka hand stop makes it easy to C-clamp the gun, dampening any muzzle rise. The SB Tactical brace is also critical, as it’s always better to have more points of contact. With these add-ons, the SP10A3 is ready to go out of the box.
