Tag Archives: bullpup

The Desert Tech MDRX

Advancing technologies have made every part of the firearm and shooting industry better, with new materials, better production equipment, and a growing competitive market all driving forward it is no wonder that so many new and exciting products are available today. Desert Tech has been pushing those limits since its inception in 2007, and this year they have released another great product that follows the Desert Tech adage Tomorrow’s Weapons.

The MDRX is the next generation rifle from Desert Tech, it builds on the already popular MDR rifle they released in 2016. The MDRX is a short-stroke piston operated semi-automatic bullpup, for those who don’t know already, a bullpup is a rifle configured such that the action, magazine, and firing mechanics are all located behind the trigger. The purpose of this design gives the MDRX a shorter overall length than conventional rifles of the same barrel length. When you add in the other additional features of the MDRX the difference becomes even more apparent.

Features
All Desert Tech rifles are designed with modularity in mind, and as such, they are all available as multi-caliber chassis and barrel combinations. The MDRX shares that same heritage, as it stands at the moment it is available in four different calibers from the factory; 223 Wylde, 308 Win, 300 BLK, and 6.5CM. All four of these barrel conversion kits can be interchanged in the same chassis, making the MDRX one of the few modern sporting rifles to accept both large and small frame calibers. All this from an SBR sized weapon without the stamp.
Being a semi-auto bullpup adds some challenges when it comes to universality, these challenges were overcome with ingenuity. The MDRX is completely ambidextrous, all of its controls are mirrored on both sides of the rifle for both right and left-handed shooters. In addition to the ambi controls, the rifle has a forward ejecting system that sends spent brass casing forward away from the shooter. Previous bullpup designs eject brass to the right side, which in a bullpup is a bad thing if you are left-handed. The MDRX can be fired from the right or left side with no concern of catching hot brass to your face. And if you are a dedicated left-hand shooter, you can swap ejection from forward right to forward left in just a few seconds.
The MDRX comes standard with a compensator made by Desert Tech called The Ratchet, the compensators are caliber specific to provide the best performance in recoil reduction and to stop muzzle rise.
One of the major challenges with bullpups is creating a good clean trigger pull, this is due to the linkage required to connect trigger shoe to the sear pack. This is another challenge that was overcome with design ingenuity, and the resulting trigger feel of the MDRX is widely accepted as great. Of the many people who have pulled the trigger on an MDRX, the common consensus is that it is a good trigger, not just for a bullpup, but a good trigger period.
The MDRX has a six-position adjustable gas valve allowing the operator to tune the rifle to whatever ammunition they might use, as well as use the rifle with a suppressor and a lower gas setting.
The MDRX’s aluminum/polymer chassis construction features full-length upper Picatinny rail, M-LOK slots for accessories and flush-mounted QD sling cups on the rear of the receiver. It is also designed to accept most AR-15 style magazines, and for large frame calibers, it uses SR-25 pattern mags. The rifle ships with caliber appropriate P-mags from Magpul.
The various caliber conversions for the MDRX feature popular twist rates, and standard barrel thread for adding muzzle accouterments. There are also both sixteen-inch, and twenty-inch barrels available in several of the assorted calibers, giving shooters different performance options. And with different barrel lengths, there are two different handguard lengths to go along.
The ambidextrous charging handles of the MDRX are non-reciprocating, they are normally locked to the front in a spring-loaded detent. They can also be locked to the rear by pulling them back and up, the release is as simple as slapping either of the handles down, and the bolt carrier closes into battery. The gun locks open upon firing the last shot from the magazine, the bolt release is centrally located right behind the magwell. This allows for very quick reloads by simply extending the thumb when seating a fresh magazine, thus closing the bolt on a fresh round. This actually can make reloading faster than most AR-style rifles due to fewer steps in the reload process.
The forward ejection system is perhaps the most curious of all the MDRX’s features. The open-faced bolt extracts the spent case and carries it to the rear, as the carrier travels it engages the ejector with a dovetail lug on either side. The momentum of the carrier then pulls the scissor-like ejector out, and it swipes across the open bolt face pushing the spent case off and into the ejection chute opposite. There it is retained by a spring-loaded pawl until the bolt carrier again travels forward where a protruding lug pushes the spent case forward and out the ejection chute. It’s a very interesting system, the only flaw I found with it is that when unloading an unspent cartridge from the rifle, it does require a firm stroke of the charging handles to get the cartridge seated firmly in the ejection chute. This is not so much a flaw as much as it is a training practice needed to be followed. The ejection system is designed to be used on either side of the rifle, both the ejector and chute can be swapped from one side to the other in seconds.

The MDRX SE utilizes a standard side ejection system

Also new for 2020 is a new side ejecting MDRX, for those who prefer a simpler, more traditional ejection pattern. The side eject is available in. 223 Wylde only, and can also be swapped from right to left side ejection. There is also the added benefit of a lighter overall weight, and a less expensive price tag.

On the Range
With several barrels in hand, I took the MDRX into my mountain hide to test its function. I started out shooting with the sixteen-inch 308 Win barrel, and loaded with Fiocchi 150 Grain FMJ ammunition at one hundred yards. After zeroing the sights, I fired a few five-shot groups, which ended up being around two MOA in size.
I continued firing the rifle at several additional targets to see how it ran. I found the recoil to be much softer than the previous similar rifles I had shot, this surely had much to do with the Ratchet compensator. The trigger was very clean and crisp, the reset is quite audible, I attribute that to the highly conductive poly receiver who’s hollow construction makes a very resonant chamber. I fired several additional groups using additional ammunition types as well, American Eagle XM80 as well as some 168 Grain match ammo from both Hornady and Federal. The match grade ammo certainly provided better groups, they averaged right around one MOA.

The MDRX seen with 20 inch 6.5CM barrel and longer handguard

So with several hundred rounds through the rifle, and a respectable shooting and zeroed rifle, I figured it was time to test the metamorphosis of this multi-caliber gifted rifle. The barrel is removed from the MDRX using a five-millimeter hex wrench, the rifle comes with one, but I prefer to use the suggested eighty-inch-pound torque limiter. After removing the handguard via two loosened screws and one take-down pin, the barrel is released by loosening the two barrel clamp screws by about one turn, and then disengaging the barrel lock 180 degrees to allow the barrel to slide out the front of the chassis. The bolt must be locked open to the rear to complete this operation. I then installed the twenty-inch 6.5 Creedmoor barrel, seating it firmly towards the breach. The process is then reversed, turning the barrel lock 180 degrees, and then torquing the two barrel clamp screws to 80 inch-pounds with a torque limiter. Followed by re-installing the handguard, which I had swapped out for the longer one. The rifle had just transformed from a sixteen-inch 308 Winchester into a twenty-inch 6.5 Creedmoor, and I was excited to see the increased performance. The point of impact would not be the same from one barrel to the next, but it was on paper at one-hundred yards, so it only took some minor corrections.
The 6.5 Creedmoor shot very well, with 140 Grain ammunition from both Hornady and Desert Tech, the groups averaged much better, in the sub to half MOA realm. With this kind of accuracy, I couldn’t wait to take the MDRX out to more significant distances.

For several hours the rifle neatly piled up brass right in front of my shooting mat, the rifle never malfunctioned, and just kept eating magazine after magazine of ammunition. I also fired some S&B 140 grain ammo through the rifle without any problems, I would have liked to try some lighter loads like a 120 grain, but I didn’t get the chance.

A typical 5 shot group from the MDRX 223 Wylde 40 Grain Fiocchi (100 Yards)

The rifle is easily swapped to smaller caliber barrels as well, the 223 Wylde and 300 Blackout do require a little more though.
A change of the bolt, a magwell spacer, and a swap of the ejection chute are required in addition to the barrel change.
The 223 Wylde shot just as good as the 6.5 Creedmoor, sub MOA groups were easy when shooting good ammo.

The great performance of the MDRX was hard to deny, it is a very compact rifle, with incredible reach, and good accuracy. Desert Tech has upped the game with this rifle, and they stand behind all their rifles with a lifetime warranty. It would be a great rifle whether you are hiding in a tree stand, need a behind the seat truck gun, or anywhere you’d need heavy firepower in a compact package. Its larger calibers are certainly useful for big game hunting and some distant shooting, while the smaller calibers are great for quick target shooting in a 3-gun style competition or varmint hunting. The MDRX carries a higher than average price tag, but that is because it brings so much more to the table. The multicaliber option alone actually saves money by consolidating your training, and less money spent on optics and accessories. You literally could do almost every American shooting activity with this one rifle. Whether it is a home defense rifle or a suppressed ranch rifle, the MDRX is a do-all rifle if ever there was one.

-CBM

The Desert Tech SRS A2

I have long enjoyed an affair with precision rifles, and one of them in particular. I fell in love with the Desert Tech SRS many years ago now, it has been through several generations since, and the latest generation is the SRS A2.

For those of you who aren’t familiar with the SRS family, it is a detachable box magazine-fed, bolt action bullpup, with the added advantage of being a multi-caliber rifle. A bullpup means that the rifle’s action is behind the trigger, and against the shoulder. This design has been tried many times over the years, in order to shorten the overall length and portability of the rifle. The SRS has all of the advantages a bullpup was designed to bring to the table, as well as the quality and a stellar record of performance sought by both law enforcement, military, and devoted precision shooters. And the icing on the cake is the multi-caliber capability.

The SRS A2 follows the long celebrated A1 model, from which it evolved. The SRS features an all-aluminum receiver, that is sandwiched between two polymer skins that comprise the pistol-grip, and magazine well. The receiver is split down the middle, and has four clamping screws down the side, together these features allow one of the SRS’s strongest assets. All SRS barrels have a shank at the breach that fits very snuggly into the receiver and is then clamped in via those four screws. Barrels are slid into the chassis from the front and seated against a steel feed ramp that doubles as an index point. The unique barrel clamping system also allows the SRS to return to zero, guaranteed every time you install each barrel, it will return to shoot the same point of impact every time. Bolts are slid into the breach by easily removing the recoil pad from the back, I say bolts because with differing cartridges you may require at least a couple of them. Anything from 223 Remington all the way up to 375XC, most options from the factory are your well-known bestsellers such as 6.5 Creedmoor, 308 Win, and 338 Lapua Magnum. The SRS has a large following with a multitude of aftermarket barrel manufacturers, allowing users to customize these factory-built rifles in whatever caliber they desire.

What’s New:

The evolution of this precision bullpup has brought several advantages to the system. One of the first notable differences of the new rifle is the M-Lok handguard, the more popular mounting system replaced the pic rail design from prior generations. The next most obvious change is the rifle’s weight, the A2 was put on a healthy diet. This new revision has the rifle weighing 2.1 pounds less than its predecessor, through various cuts and shaving material where possible.
The trigger also received an upgrade, a new design they call a “field match” trigger. This new trigger is adjustable from 1.5 to 7 pounds.

The SRS A1 featured a built-in retractable monopod in the bottom of the butt-pad, many users found this monopod to be a very valuable tool because of its quick deployment, and both coarse and fine adjustments. The A2 model was designed to be lighter, and the monopod was then made optional equipment instead of standard. That also helped lower the overall weight of the rifle.

The new M-Lok handguard is also interchangeable. The A1 handguard was difficult to swap between different length handguards, and it required a proprietary tool from Desert Tech. The new SRS A2 handguard is user-replaceable using only a Hex Key wrench, this allows users to easily swap between the standard length (longer) handguard, and the shorter length (Covert) handguard. Desert Tech sells the separate handguards as a kit for end-users to install, so they can enjoy the benefits of either configuration.

In addition to the new rifle chassis, Desert Tech will be releasing a few new calibers specifically marketed towards big game hunters. These newer barrels are chambered in popular cartridges such as 300 RUM, 300WM, and 7MM Rem Mag with more to come. A lighter contour barrel also helps lower the overall weight of the rifle. With a lighter rifle, the SRS is now even more appealing to those of us that would like to hunt with it, so these new offerings are a welcome development.

What’s the same:

The SRS A2 being a direct descendant of the A1 means that it inherited some of its best traits. The barrel mounting system is the same, which means that the barrel collection most SRS owners enjoy, can be used in the new A2 chassis as well. Bolts, barrels and magazines are also interchangeable between the two rifle chassis. This is a very welcome feature to SRS aficionados, as barrel kits can cost anywhere from 800 up to 2000 dollars.

The barrel clamping procedure remains the same, there is a barrel lock on one side of the receiver and four clamping screws on the other. The barrel lock rotates 360 degrees, but has a detent on the lock and unlocked positions. After installing the barrel in the chassis, the barrel lock is rotated to the lock position which rotates a cam to hold the barrel in place. The four clamping screws are then torqued down to 80-inch pounds.

The SRS A2 Covert with my 18” 6.5 Creedmoor

The A2 maintains both standard length and Covert models as was the A1, the Covert model allows for using shorter barrels like the very popular sixteen-inch 308 Winchester. The longer standard handguard, allows for further forward bipod mounting, as well as clip on night/thermal optics.

The adjustable comb height adjustment stays the same, as does the spacer system to adjust the length of pull. These features are easy to adjust and allow you to fit the rifle to you.

On the Range:

Being quite familiar with the SRS platform, I found almost everything about it to be very recognizable. All the same functions I was used to, I tried several of my older conversion kits in it with great success. One thing I didn’t miss at all was the weight, the couple pounds lost make the rifle noticeably lighter. And the new hunting profile barrels are lighter than I was used to, making the whole kit seem more friendly to hiking hunters.

Clockwise: The new Field Match Trigger, fluted bolt body, M-Lok handguard with QD sling receivers, handguard mounting screws.

Desert Tech claims the A2 to be even more accurate than its precedent platform, this was a claim I wanted to see for myself. The SRS has always been a very accurate rifle in my experience, half MOA groups are expected and even guaranteed by Desert Tech when using match grade ammunition.  The accuracy guarantee for the A1 SRS was half MOA, I was surprised to find that the A2 did not come with a better guarantee according to Desert Tech’s 36% better accuracy claim for the A2.

Shooting the SRS A2

I shot several different barrels in the A2 while at the range, among them were 6.5Creedmoor, 308 Winchester, 300 Remington Ultra Magnum, and 300 Winchester magnum.  The new hunting calibers were all the lighter contour, this made the felt recoil a little more aggressive than I was used to, but with muzzle brakes installed the recoil was very manageable. Accuracy was everything I expected it to be from the SRS platform,  typical groups were half MOA. Ammunition types gave wildly varying results, some of them did not even shoot MOA, while others easily shot sub half MOA.  I can’t say for sure if the lighter barrel contour had anything to do with it because when they had the right ammo they just shot great.

A typical five shot group from the SRS A2

My fourteen-year-old son also shot the rifle a bit and carried it around, he too seemed pleasantly surprised by the rifle’s easy handling and modest recoil.  As usual, the rifle shot better when the sound suppressor was installed. The Desert Tech suppressor mounts directly to the muzzle brake and provides hearing safe shooting with enhanced accuracy. Another moment the bullpup platform shines is when a suppressor is installed, the SRS A2 with a suppressor mounted is still shorter than comparable rifles without one.

Whether shooting inside a 100-yard underground tunnel or shooting 1200 yards across a breezy mountain ridge, the SRS A2 tackled targets with great ease.

Detractors

The only problems I found with the SRS A2 were not so much problems as they were questions. Previous generations of SRS rifles had fully adjustable triggers that were serviceable in the field with a simple Allen wrench. The new trigger requires disassembly of the chassis to complete the adjustment. While an infrequent necessity, it is still an unwelcome one.

Final Thoughts

The SRS A2 is a pleasant breath of fresh air that I didn’t even know I needed. It appears Desert Tech has listened to consumers and delivered a better bullpup, my A1 wont be going anywhere soon, but it definitely needs an A2 to go with it.

-CBM