While casual or occasional gun buyers’ attention is taken up by all of the new doodads and widgets they can screw or bolt on to their AR-15 style rifle, those with a bit more of a critical eye were watching the slow but steady arrival of the roller-delayed revolution. What we’re witnessing is a tidal wave of new manufactured, not surplus guns built on the HK roller-delayed blowback action. There are several companies providing these guns and Century Arms is one of them.
From my perspective, I have appreciated the CETME/HK design for about 25 to 30 years now, since a time when Century Arms was bringing in semi-auto models built with original surplus parts at fantastic prices. I can recall going into my favorite gun shop and finding a semi-auto CETME 7.62mm NATO rifle priced around $350. I couldn’t believe it was so inexpensive. “What’s wrong with that gun?” I inquired. The gun shop owner laughed, “Nothing is wrong with it. It’s just a good deal.”
Century Arms AP5 Series
In addition to the CETME and G3 full-sized rifles that Century Arms has had in stock at various times over the decades, they’ve had the AP5 line for several years now. Initially, I picked up the original AP5 pistol, which is a clone of the HK MP5 or SP5, and reviewed it in articles and videos. The AP5 line incorporated two, then three models, all in 9mm for several years. And then something changed.
At the 2025 SHOT Show, I walked into the Century Arms booth and was surprised to find not one, but several new models in the AP series. Their catalog now includes five 9mm models as well as the new AP51 in 7.62mm NATO and the AP53 in 5.56mm NATO. Each one of those guns is built on the tried and true roller-delayed blowback action. Of all the models on display at SHOT, though, it was the AP5-SD that really got my juices flowing.
AP5-SD
Just in case you’re new around here, the HK MP5SD is an integrally suppressed version of the classic MP5 submachine gun. In the business, the MP5SD is widely known as the quietest 9mm sub gun in the world. When using the 147 grain subsonic ammunition, the only noise produced is the metallic sound of the actions moving and then the “thump” of the bullet impacting the target.
Credit goes to the US Navy SEALs for being the first ones to embrace the 147 grain subsonic 9mm and to adopt the MP5SD. The 1990 movie “Navy Seals,” with Charlie Sheen and Michael Biehn also features the HK MP5SD prominently.
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 uses 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.
When I unboxed the gun after it arrived at our FFL, inside the padded hard case I found the gun, two 30-round magazines, a sling, an aluminum optic mount with Picatinny rail, a cleaning kit and owner’s manual. Century offers their AP5-SD with or without the option of a Magpul pistol brace. The version I had included the retractable brace. When you get the braced version, Century Arms includes the standard end-cap as well and you can switch them out if that is something you want to do.
Don’t be fooled by the “Navy style” grip assembly. The gun is semi-automatic, but to be faithful to the original, the 3-round burst and auto modes are depicted.
Also, the iconic MP5SD shrouded handguard with a rubberized grip truly completes the package.
Range Time
On a sunny Saturday afternoon in the mountains, my oldest son Jarrad and I loaded up the truck with targets and ammo to give the AP5-SD a good break-in. My experience with roller-delayed blowback actions is that they like to be run wet, so before we fired the first shot, I pulled out the action and applied a fair amount of lubrication. (NB: If this is your first roller-delayed firearm, be sure to consult the owner’s manual. These guns do NOT disassemble like your GLOCK or AR.)
Additionally, my experience with sub guns, whether Colt, Uzi, Sterling, or HK, has always been that they prefer FMJ 9x19mm ammunition. For testing I had a big green ammo can filled with FMJ 9mm from Black Hills, CCI, Winchester and some of the Red Army Standard gray steel cased ammo from when that was available.
As mentioned earlier, this isn’t my first MP5 style firearm, so I had several additional magazines in my Original SOE Micro Rig. The SOE rig holds four sub gun mags, has a utility pocket where I keep a Pocket Life Saver trauma kit, as well as an internal map pocket, straps and loops to add accessories.
Jarrad and I took turns stuffing magazines. A word of caution…if you’re going to purchase one of these guns, go ahead and order a case of 9mm ammunition. Once you start shooting, you aren’t going to want to stop.
For the uninitiated, when you load an HK-style roller-delayed action, you first lock the bolt open by pulling the handle back and rotating it up into the notch in the receiver. Then you insert the magazine and give the bolt handle a slap, just like in the movies. The “HK Slap” is not just a Hollywood thing, it is actually how you work the gun.
Using all of the aforementioned ammunition, we experienced a total of…zero stoppages. None. The iron sights were right-on from the factory. First we addressed a steel half silhouette and then we engaged an 8-inch round plate. From forty and fifty yards, hits on the plate came with monotonous regularity. If you aren’t hitting the target, it’s not the gun, it’s you.
After a few hundred rounds, Jarrad and I both agreed that the AP5-SD performs exactly as advertised. We had no issues and the six plus pound weight of the gun reduced recoil to the point where you barely noticed it.
Parting Thoughts
If you’re getting bored with your striker-fired pistol and your AR, I would strongly suggest that you join us in the Roller-Delayed Revolution. Century Arms has a battery of guns from which to choose. If you decide on the AP5-SD, I doubt that you will be disappointed.
Specifications: Century Arms AP5-SD
- CALIBER – 9mm
- WEIGHT – 6.7 LBS
- CAPACITY – 30+1 Rounds
- MAGAZINE TYPE – AP5 style magazine
- REAR SIGHT- Fully adjustable
- MUZZLE – Removable faux suppressor
- MAGAZINES INCLUDED – 2 30-Round magazines
- FINISH COLOR – Black
- OVERALL LENGTH – 30 inches
- ACTION TYPE- Semi-automatic
- STOCK MATERIAL – Synthetic
- BARREL LENGTH – 5.75″
- MADE IN – Turkey
- MSRP – $1799.99
too bad about that whole meleagris thing.
i’ll never be bored with my striker fired or di anything.
delayed is good; i’ve heard century badmouthed since i can remember.