REVIEW: Century Arms AP5-SD “Enhanced” Pistol

The new Century Arms AP5-SD is a “Cold War cool” clone of H&K’s iconic MP5SD. But could our evaluator leave well enough alone? Silly question!

by Paul G Markel

There are several iconic firearms in world history, those that everyone knows just from their shape or silhouette. The AK-47 and the AR-15 come immediately to mind. I would argue that of the Top 5 most iconic firearms of the last century, the Heckler & Koch MP5 rightfully holds a place in that ranking.

As a proud, card-carrying member of Generation X, I grew up watching action heroes and villains alike slapping the charging handles of MP5 sub-guns on both the big and small screens (Gen Z, I mean movies and TV). Take a moment, if you will, to think back to where you were first exposed to the black German beauty that is the HK MP5.

For my part, I recall the black and white photos in the newspapers, particularly the famous balcony scene, of the British SAS takedown of the Iranian Embassy the first week of May, 1980. Wearing all black, with gas masks covering their faces, the SAS commandos stormed the Iranian Embassy in London. With their soon-to-be-famous MP5 submachine guns in hand, the commandos rescued the hostages, killed all the terrorists but one, and cemented the fame of that 9x19mm HK blaster.

The Iranian Embassy siege was significant because the event played out with the press in full attendance outside with still and motion picture cameras capturing what went on — at least on the outside. Remember kids, there was no internet back then. Also, it is worth noting that the British Special Air Service commandos, formed during WWII, were essentially a secret or clandestine organization. The Iranian embassy siege was the first “public appearance” of the unit.

MP5SD…the Sexiest Version?

Developed in the early 1960s and officially released in 1966, the original MP5 9x19mm submachine gun was widely adopted by NATO countries, particularly their anti-terrorist units. HK offered numerous models and modifications for the MP5, but the one that I believe ranks as “The Sexist MP5” has got to be the integrally suppressed MP5SD.

When I was a young lad, seated at the knees of the masters, it was thoroughly accepted that the MP5SD was the quietest submachine gun in the world. When loaded with subsonic 9mm ammunition, the only perceptible sound when the gun fired was the movement of the bolt. The US Navy Seals jumped on the MP5SD like a fat kid on a donut and soon, the German sub-gun became the go-to blaster for Seal Team Six.

Review: Century Arms Ap5 Sd “enhanced” Pistol — H&K’s current MP5SD in its full-auto, integrally suppressed glory.

In the year 2025, there are indeed “transferable” MP5SD submachine guns out there. Expect to shell out between $30K and $50K, depending on the dealer or auction house.

But what about the average Joe, those who don’t have $50-grand of disposable income? Is there an option for you that can fill the empty hole in your heart that only one of these Cold War-era beauties can?

I am glad you asked that question.

Century Arms AP5-SD

For those who may not have been paying attention, Century Arms has been bringing in exact MP5 replicas, minus the happy switch, built on original Heckler & Koch machinery, for several years now. First, they had two guns in their “AP5” line, then three; however, at the 2025 SHOT show, Century unveiled four new models to include the ever-so-sexy AP5-SD.

The Century Arms AP5-SD is a faithful, semi-automatic replica of the MP5SD as it uses a “faux suppressor.” Technically listed as a “pistol,” the AP5-SD requires no special handling or tax stamp. Anyone residing in Free America can purchase one. As with the entire AP5 series, the AP5-SD is built with HK machinery and the 9mm versions use the original-pattern MP5 magazines. Yes, the faux suppressor can be removed from the barrel, which has 1/2×28 TPI RH threading. If you have a 9mm can of your own, you can easily install it.

Inside the padded hard case you will find the gun, two 30-round magazines, a sling, an aluminum optic mount with Picatinny rail, a cleaning kit, and an owner’s manual. When it comes to the AP5-SD, Century offers the gun in two configurations: standard, and with the option of a Magpul stabilizing brace.

Let’s examine the standard option that has an MSRP of $1699.

AP5-SD Enhanced

In the out-of-the-box configuration, the AP5-SD ran just fine, and iron sights were right on from the factory at 25 and 50 yards. After my initial range time with my son, Jarrad, I knew that I wanted to enhance the pistol by adding some aftermarket features. Let’s consider the following enhancements.

It is no secret that I am a fan of SB Tactical and their products and have been for essentially as long as the company has existed. The stabilizing brace from SB that goes with the AP5-SD like peas and carrots is the HKPDW retractable version. All that is required for installation is the removal of the factory backplate by pulling out a single HK pin. The SB HKPDW slides right on and secures with said pin. No tools or modifications needed. There is absolutely no slop in the retractable rails, yet I like to put a few drops of lube on the inside of the rails to smooth their travel. Also, there are QD sockets on the left and right of the brace housing — a nice touch.

Onto the receiver I installed the aluminum Picatinny optic mount. All the hardware and the Allen wrench are included from Century. As with all threads on firearms, applying a small amount of threadlock is a prudent choice. With the optic rail in place, I added a tried-and-true EOTech Model 552 HWS (holographic weapon sight).

The faux suppressor was easy enough to unscrew and remove. In its place, I would add an AAC TiRant 9mm suppressor from the days when AAC was its own company. If you have a 9mm can in a normal handgun configuration with the spring driven “booster,” you need to remove the spring and replace it with a fixed spacer. Otherwise, your can will “beat itself to death” during recoil. The maker of your can will have a spacer for you if you don’t already have one. The barrel of the AP5-SD is recessed a couple of inches into the forend, and the fit of the suppressor is perfect.

While the AP5-SD comes with two MP5 style mags, I felt that extra rounds never hurt. I have been wanting to try out the Magpul D-50 MP drum since that company introduced them a couple years ago, and this was the perfect opportunity to do so. The Magpul drum magazines load in a different manner than your standard affair, but they are not difficult to fill, despite what some crybabies on the internet have said. It took me about five minutes to load a full box of 50 into the drum.

Range Time

Out of the box, without a real suppressor, Jarrad and I put about two hundred rounds of various 9mm FMJ loads through the AP5-SD with zero stoppages using the included factory magazines.

My experience with roller-delayed guns, such as the AP5-SD, is that they do not like to feed JHP or any 9mm ammunition with a flat or open face. The 147-grain TMJ subsonic with flat noses falls into this category, as do the vaunted Hydra-Shok rounds. I’m not saying they jam every shot, but reliability has proven to be less than stellar based upon my experience with numerous guns from varied makers. And so, all my test ammo consisted of traditional pointed 9mm bullets.

With the AP5-SD in the “enhanced’ configuration, I zeroed the EOTech HWS optic at about 25 meters. That task complete, it was time to ring some steel targets.

To honor the SAS commandos discussed earlier in this piece, I decided to do most of my range drills in full kit to include wearing a field protective mask (gas mask). This particular mask is a new model CM-7M mask from Mira Safety and has the dual lens or goggle-like set up reminiscent of those used by the SAS during the Iranian Embassy siege. I did have something going for me that the British commandos did not have — an EOTech HWS optic.

For those unaware, the dot/circle reticle of the EOTech is a protected hologram, ergo HWS (holographic weapon sight). What that means is that, once zeroed, it does not matter where you “perceive” the reticle to be in the sight housing. So long as you put the dot on the target, you get hits. For unique situations, such as when wearing a gas mask, where you cannot get a traditional cheek weld, the EOTech HWS system is perfect.

All the traditional 30-round MP5-style magazines did well. My experience with the Magpul 50-round drum was that, with a full 50 rounds loaded, I would get a stoppage/failure to feed after the first one or two shots. I repeated the process, and it was consistent; however, if I download to only 46 or 47 rounds, the drum magazine ran smoothly. How big of a concern is this? You decide.

As for the AP5-SD in the “enhanced” configuration, the gun ran as expected. Use of a genuine suppressor made it hearing-safe despite the supersonic crack of the bullets. The SB Tactical brace was a perfect addition and the EOTech optic made shooting a pleasure, with or without a mask on my face.

The bottom line is simple: the semi-automatic AP5 guns are tremendously enjoyable to shoot and offer the user the feel of the traditional Cold War-era sub-guns. The AP5-SD configuration is one of the most attractive offerings in Century’s AP5 product line.

Century Arms AP5-SD Specifications