Good to see Desert Tech finally got around to fixing a lot of their initial teething problems, ramping up production, and offering the 6.5 Creedmoor option.  Their 20" barrel looks pretty darned nice, and there are a few youtube video's out there that show some real promise.  This will never be the 0.5 MOA gun (I don't think at least), but for what it is, if it can be a 1 MOA, or even a 1.25 or so MOA gun, that's actually still quite interesting to me.  It looks like it is (?).    Curious if anyone here has one and has played with it any?

They aren't cheap; but in some ways, they aren't that expensive either.  A Steyr AUG in 5.56 runs about $2K, which is about what the MDRx is going for; and in 6.5 CM.  Or at least seems to be kind of close.  Tavor's are priced comparable as well.  And I get the feeling the MDRx sort of beats the TAVOR7 in every category (yes?).

One item in particular, is when playing with an HBAR 6.5 CM AR10, I find shooting such a rifle off-hand to just be downright hard.  The thing is so heavy, doing snap-field shooting is tough.  The MDRx is not much lighter (9lb w/out optics, in the 6.5 CM version), but as a guy who's shot an AUG a lot, I find the bullpup weight balance is such that you can be pretty comfortable shooting off-hand, even when it's heavy.  So I'm hopeful the same on this gun too?  From the youtube videos again, I'm seeing people appearing to be able to run and gun with it pretty well, which is encouraging to see.

I will say, I wish someone would do a 6.5 Grendel in bullpup, as to me THAT would be seriously cool kit, especially if they kept it light.  But 6.5 CM in bullpup semi-auto is very interesting to me.

To follow-up;  I have a RPR in 6.5 CM that shoots sub MOA, with damned near anything.  However, I find it considerably more difference to do so with a 6.5CM AR10, and very much so more difficult to do so with the MDRx.  The MDRx s a very cool concept gun; and youtube personalities firing .223 through this .308 chassy sized gun report good results.  But in general, run it with full house loads for which it was made, and it just doesn't shoot that tight at all.  For comparison, from another thread, here is an assessment of some 2021 testing with different load conditions, demonstrating both the actual definitions of accuracy AND precision of each rifle with different ammunition in each.  

RPR with a spectrum of ammo - zero'd for one, and then all others fired using same zero.  Overlay of point of impact (location) and circle size (group size)


PA10 6.5CM with a FAXON 20" Gunner BBL


MDRx with a spectrum of ammo - zero'd for one, and then all others fired at same zero:




As one can see the RPR POI and accuracy doesn't shift much.  Even S&B 140 FMJ (a cheap 59 cent option - for a time), isn't bad.  However in the AR10, things open up a good bit.  There seems to be more of a skill to shooting an AR10 well, than a bolt action, and I am still trying to master that.   It still CAN shoot well, but accuracy and precision both open up.   With the MDRx, it's basically a trainwreck, by a Precision Rifles subforum standard at least.    A shame since the concept is a CBQ/1000yard/1200yard/hunt-to-500yard/do-all gun, all from the same magazine even when in 6.5CM.  And it is by far the most pleasant and my favorite .308 chassy rifle to handle and fire; and mine at least is strikingly reliable - it basically never jams (unless I'm monkeying with the gas system or other user-induced obvious item).  Yet, the accuracy is a challenge.  There are two issues at play - for one, the who rifle system apparently flexes and just randomly will throw a round (or several rounds) laterally by 5 MOA at times.  It's quite striking.   The other issues is the whole gun flexes and you can literally bend/move the barrel with your hand (yes, i've pulled it out and retightened many times, even sent back to factory once).   The reality is, in it's current form, this is the MDRx in 6.5CM.  And I've yet to see anyone report any better once they actually start to study and document it.  

I have been working on tuning that...   After this, I will update this weekends performance.

AR10 in 6.5 CM 20" FAXON BBL (for comparison to MDRx)
So this weekend I did take the AR10 and the MDRx out anew, and did a spectrum of bench firing at 500 yards on digital targets, to track performance.



Which, one of its better groups, is this decent run of 140 gr HPBT Nosler rounds.


To be fair, there was some lateral wind, and while 100 yard testing is nice; things like that do show up at 500 yards, so it's possible some of the 9s are actually good shots and just bleeds due to wind.  Performance on target at 500 yards is actually pretty decent - though not spectacular.

MDRx 6.5CM 20"  
(actually FAXON makes the barrel, if I understand correctly; and btw, they botched some of the initial barrels with rough chambers, hence the reliability issues some had at first - mine runs 100% pretty much no matter what I feed, I know that).


For comparison, here is the MDRx.  I will say, I've spent considerable time doing load development trying to get this unique and fascinating rifle up to its full accuracy potential.  How am I doing?  Meh; I've managed to tune out with great care the tendancy to just randomly throw rounds completely off the scoring rings into MISS category shots.  And I have found that while zero changes DRAMATICALLY based on what load I'm shooting, the return to zero for any particular load is actually pretty decent.  Even if I pull the barrel and put it back on, it's pretty close.  Within the error of it's group size (which is kind of assisted by it's rather large group sizes).  







The problem with the MDRx is the chassy is not strong enough to prevent excessive flex between the end of the barrel, and the scope.  Somewhere in that equation, it's flexing - randomly.  It's exasperated by the design-flaw of putting the gas port too close to the chamber, resulting in excessive force and high pressure (and early movement), unnecessarily.  They need to redesign and MDRy; with a 2-3" longer gas-system port location, and just a tiny bit of extra strength in the trunion/receiver section.  But, in the meantime, this is the only ambidextrious 6.5CM factory rifle on the planet, and it's actually a really fun gun to shoot with very pleasant recoil and handling, compared to an AR10.  So I spent some time tuning loads to meet that.  I found that running a relatively fast powder in a mild load with a light bullet, helps tame the flex flyer issue, and sort of helps with accuracy.  Here is the performance with my current two best developed loads specific to this rifle:

107 SMK with 4895 powder


129 H SST with 4064 powder


Grid is MOA, so as you can see, accuracy is on the order of 2-2.5 MOA.  Throw out the flier (which you don't actually get to do, so kind of lame to even say), and it does get better.   That's .. serviceable accuracy actually, though not what many would call Precision Rifle forum accuracy.  No Bullseye competition with this one; though maybe some gong-range shooting out to 1200 yards, depending.  but yea, that's about as good as you are going to get with an MDRx at 500 yard operating as intended (.308 class rounds).  I look forward to someone showing me wrong and coming up with an even better load!

In the realm of 7.62 bullpups, the MDRx certainly appears to be a good option.  The problem is that it’s still being modified and tweaked to work properly and to the standards that customers were expecting from DesertTech.  The start of this rifle debacle goes back to 2014 and the first delivered rifle wasn’t until 2017.  The first fully working current model that didn’t need re-engineered replacement parts wasn’t until about 2020 or 2021.  I was among the group that pre-ordered and crowd-funded the MDR back in January 2016.  I waited over a year with repeated delays until finally I had enough of DT’s stalling and began the arduous process of trying to get my deposit back.  They ghosted me until I put them on blast on Primary&Secondary in 2017 and then suddenly I had a response to my emails and voicemails.  It took 20 months for the first MDR to be delivered, and within a very short time they had to ship new parts for it because parts were breaking and the rifle had feeding issues.  I was happy to have my money back, and when I saw that this rifle was not even close to being MOA capable, I was even happier I got my money back.  

It’s a unique rifle, and if DT has worked out their reliability issues, good for them.  Now they can get to work on their accuracy issues because 2-2.5moa is not acceptable for a modern rifle.  There’s no way they can compete with large frame ARs in terms of accuracy.  It’s nice that you can swap out calibers, that’s not hard to do with ARs either.  You just swap out uppers.  Or you buy an LMT MWS.  If you the best you can shoot is 2moa, there’s really no point to getting a 6.5CM then because the ranges where 6.5CM comes into marked advantage over .308 is around 800yds, and by that point you have a 16” spread with a 2moa rifle.  I just don’t think there’s a point to DT making a 6.5CM if they can’t make it accurate enough to capitalize on a high-BC cartridge.  

I would still rate the Tavor-7 as a better rifle. IWI put out a rifle that worked from the start, and they have a far more substantial R&D capability.  The Tavor-7 may not be as modular as the MDRx, but as I mentioned above, there’s no point to modularity when it offers no advantage.  If I can’t have sub-MOA accuracy with either rifle, then I want the one that has been reliable over the one that has required repeated re-engineering AFTER the rifle was released.