Derya Mk-12 Semi-Auto Shotgun

Keeping abreast of the latest Practical/ Action shotguns is getting more problematic, due to their prolific nature of this near solely, Turkish-made and dominated sector. And although I have tested all four incarnations of the Akdal 1919, plus the Saiga 12, Molot Vipr and Hatsan Raider, I missed out on the UTAS 12 and Typhoon. So, I was pleased to get in touch with NDH Firearms (Dean Holgate) as he’s importing and distributing the latest Turkish Delight – the Derya Mk-12. From what I was told, Derya are the originators and inspiration for the M16-like UTAS and Typhoon guns. However, my research showed Derya’s earlier Mk-10, which is very much like the Akdal 1919 series, with its gas piston operating system. Plus, and though all M16-like designs the Mk-12, UTAS and Typhoon are a little different in terms of the operating system, with a simpler and more efficient mechanism.

Lots of extras

The gun arrived in a padded, plastic transit case with a lot of accessories. You get Magpul MBUS-type fold-down sights, D-Handle (combined AR15 rear sight and carry handle) and a pair of 45⁰ off-set irons.

So, if you have a scope on top, when you get up close you can flip the gun on the side and access those irons too. They have Picatinny bases, so you could remove the sight and fit a red dot. But there’s more, an elasticated single-point sling, sight adjusting and fitting tools, cleaning cloth, Derya’s angled fore grip (AFG), combination tool with choke wrench, three, flush-fit chokes – Full, Modified and Cylinder. Plus, three magazines 2, 5 and 10-rounders, a set of ear plugs and a 2-year guarantee.

Now to the main event – the Mk-12. Though most Section 1 shotguns are a tad bulky, the Derya is less so, given its simpler operating system, as we shall see. Naturally, the butt is a telescopic CAR15/M4-type. Keeping it legal, minimum overall length is 41” with a 24” barrel, UK law says a shotgun must conform to the minimum dimensions of 40/24”. Like all of its ilk, it’s not small but feels handier than some.

Nuts and bolts

The build is substantial, with solid upper and lower receiver assemblies and a 12.75”, 4, way Picatinny forend; it’s not free-floating, as a nut that screws directly to the barrel keeps it on. This item is different looking to what Derya shows on its website, with a more waisted design and just front and rear Picatinny rail sections. The feel is not too aggressive, and you can always fit rail guards. The butt is a more basic L-shape, with a rubber recoil pad and heightadjustable comb. Length of pull (LOP) goes from 11.75 – 15” in four increments. The pistol grip is an A2 type (with single finger grove), but the lower receiver is deeper than normal, so might preclude the flush fitting of an alternative AR handle.

Controls and features show a standard AR layout, with a small, single-sided safety catch on the left above the grip. The manual bolt release/hold open is on the left behind the mag well and shows a large/concave thumb rest. On the opposite side is the mag release button with a big head plate on the side of the mag well. The trigger guard is enlarged for easier access and two sling slots are fitted on the left; one at the buffer tube receiver junction and the other on the 9 O’clock rail. The bolt-mounted cocking handle is reversible, as there’s a corresponding slot on the left of the upper. It has a Buffer Bolt System (BBS), which is said to reduce felt recoil a bit, and consists of what looks like a hard rubber pad at the rear.

Life’s a gas!

The Mk-12’s safety catch is live all the time; meaning that with the hammer un-cocked it still works. So, with the hammer down and the safety ON, you cannot cock the action; take note. The operating mechanism is a bit different from the standard, ‘connected’ gas piston system we are more familiar with.

Rather than being slung underneath like the AKDAL or Hatsan Raider the operating mechanism is wrapped around the barrel and is of the short stroke tappet-type, as there’s no fixed connection to the bolt assembly. In this, it’s like the Browning Maxus, though here it’s underslung due to the fact this gun uses a magazine tube. Unlike more conventional guns, the Mk-12 takes its gas from approximately 1/3rd of the way up the barrel, which means it’s at higher pressure, which should result in more reliable and versatile operation with varying power cartridges.

Tap tap

There are three radial, gas ports drilled at 45⁰ around the barrel, over this is a gas collar that is retained by a split washer in a cannelure. Inside this is the free-floating, top hat piston and behind, the operating tube with two extended lugs at the end. As the gun fires, gas enters the shroud and knocks the piston rearwards, which imparts a blow to the operating tube that moves back and hits the carrier, so initiating the unlocking movement. The carrier has a long rat tail that compresses the spring in the buffer tube, so storing energy for the return stroke. In use, over a wide range of ammo, from 28-gram # 7 and 8 loads through heavy AAA and OO buck shot and different slug types proved very reliable, with all ammo giving last round hold open energy.

However, filling these big magazines is always hard work when they are new, as you need a big spring to shift a column of 10 shells with a lot of thumb busting required to get them all in. Best is to fill them up and leave overnight to loosen things up. In testing, this was the only time I had stoppages, either with the first empty not fully ejecting due to the strong upwards pressure from the mag, or the second shell being pushed up too hard by the one below, which caused misfeeds. However, this symptom soon stopped, and I can say I had 100% reliability afterwards.

Push and pull

Last round hold open worked fine, but the manual bolt release catch, even with its big head button, proved very stiff to operate, I found it better to thump it with the heel of my hand. The mag button was similar, and the empty would not always fall free, however, this eased up after about 200-rounds. Felt recoil was acceptable with the shot loads and some CBC round ball slug, with control aided by fitting a vertical forward grip. The real test was some Winchester Supreme, Sabot, Partition Gold 385-grain, 2¾”, which was still nasty but not as much as in other guns. Also, heavy, was the trigger pull, at an overly firm 8 lbs, although it was useable once understood. The safety catch is a tad small and needs a bit more meat/length on the lever to get your finger on, I’d have preferred an ambi unit here! Slug accuracy was good with a Hawke 1-6x24 Frontier 30 with Tactical Dot AR reticle and bipod fitted, the CBC was printing 2-3” at 100m.

Take down

Stripping was a bit confusing, as the Mk-12 opens like a real AR by pushing out the body pins, once the forend is off. I expected to be able to remove the bolt from the rear; not so! Forend and gas system off first, the combo tool has a C-spanner for the barrel nut, then pull back the gas collar, remove the split washer and then slide it off along with the piston and operating tube. Next, the barrel, which is retained by a castellated nut that screws into the front of the receiver. First, you must remove the locking Allen screw from underneath/between the forward hinge pin holes and with the tool use the other spanner end to remove collar and pull it clear. Then, pull out the cocking handle (very stiff), which frees the carrier/rat tail assembly from the bolt, which comes out forward with the carrier going either way.

Jobs like this are for the bench when you have time and it’s easy to keep the gas system clean, not that it gets very dirty either! Overall, I liked the Mk-12, mainly due to its excellent reliability over a broad range of ammo and handling. The heavy controls are a niggle, but I can put up with them, suffice to say, if I were young again and shot PSG, I’d get one!