I recently (8/28/2021) purchased a Desert Tech MDRX 308 from the Hub in Show Low, AZ. I took the rifle out the same day and immediately began experiencing malfunctions with the rifle. I had a friend with me who is also familiar with weapons and he had the same issues. I contacted the retailer who advised me to bring it to them. After servicing the rifle and testing it themselves they indicated that there was something wrong with the brand new rifle but that I would need to contact the manufacturer for warranty issues. I contacted the manufacturer and when they eventually returned my communication, they indicated that “All our firearms come with a transferable lifetime warranty” and advised me to send it to them for warranty repairs. The following is a summary of my experience:
Initially the magazine would eject after firing a single round. Any size magazine too. I bent and filed the magazine catch to enable it to work temporarily. Desert tech replaced it on the first warranty claim.
On the first day of shooting one of the screws fell out of the left hand side of the rifle, in the desert, and was lost. DT replaced it on the first warranty request.

The most persistent problem is the cycling of ammo or frequent jamming. I have tried several manufacturers of 308 rounds Norma, Winchester, Fiocchi, PMC to rule out ammo inconsistencies. And since the rifle is advertised as dual ammo compatible I also tested 7.62 x51 Magtec, Armscor, PPU. The most problematic 308 round is anything with a soft tip intended for hunting. The gunsmith I took the rifle to after 400 rounds stripped it, cleaned it, lubed it and tested it on his range with the ammo he had and experienced the same issues I had in the field. The manufacturers advise to me was that “the rifle is not fully broke-in until 1000 rounds have been fired thru it” and recommended I put more ammo thru it. It did not chamber correctly at 1000 rounds and still fails to function at 1500 rounds.
The PMC and Winchester 308 ammo initially used tended to lightly dimple and not fire the primer on the second round chambered after the first is fired. I suspected the rifle was double firing. After inspecting the factory trigger assembly I notice what appears to be excessive wear, given only 400 rounds had fired at this point, to the trigger assembly. After each round fired the factory trigger has a latch that catches the hammer so it will not fire again. This latch is cutting a notch into the hammer shaft. When you rack it back to clear the unspent round from this issue the rifle doesn't always kick out the cartridge like normal, even if you rack it fast and hard. The unspent round and the next round in the magazines end up jammed in the chamber together sometimes.
I replaced the factory trigger with Jard Sear trigger, and it came from the manufacturer out of adjustment, not DTs fault but while out of adjustment it produced the same 308 double fire as I described above. The rifle fires the first round, chambers the second and let’s go of the hammer. When you eject the unspent second round it is lightly dimpled. The rifle will also insert two rounds in the chamber if you just try to clear the unspent round with the magazine still inserted. After adjusting the disconnect screw on the new trigger the riffle fires 308 PMC solid tip more consistently and while on the Normal gas block setting. When the rifle was sent back to the manufacturer for the first warranty request it had the factory trigger installed and they did not do anything to it but apply more grease. It still looks excessively warn and I only use the Jard trigger moving forward.
I also noticed the trigger would occasionally get stuck after pressing it. In some cases just waiting a second would allow the trigger to spring forward and on others the rifle had to be tapped or beat on to release the trigger. Basically the rifle is acting as if I am holding the trigger for a prolonged period of time before resetting and letting me pull the trigger again. I don’t believe this issue is related to the above issue as the factory trigger has a secondary latch to catch the hammer if after cycling a live round there is still a finger depressing the trigger. And it appears to be working properly. Upon inspection the trigger rod that connects the front group to the rear assembly has metal burs on the rear of it that appear to be catching on the plastic guides inside the rifle. I removed the rod and polished it smooth with a file. No more sticking but DT has also not made mention of this issue.
Only rarely did the 308 cartridge miss or get stuck in the forward eject system or chamber. The 7.62 x51 ammo I tested before sending the rifle in the first time frequently got stuck in or missed the forward eject system. The PPU 7.62 x51 ammo I initially tested frequently got stuck in the chamber and if the gas block was not turned down the riffle will rip the rim off the cartridge stuck in the chamber. The rifle cycles nicely if you leave the original forward eject port off allowing the 7.62 x51 cartridges to fly freely out of the side and lubricate every round. DT replaced the forward ejection panel on the first warranty request. I was able to get 43 rounds of 7.62 x 51 through it afterwards without any jams related to the new forward ejection panel.
On the second day of shooting the cartridge ejection port dust cover hatch started to fall apart. The pin worked it's way nearly out and it stopped working correctly afterwards. The latch doesn't hold it closed when you want it closed and the spring doesn't hold it open when you want it open. The 308 cartridges appear to push past it regardless and I usually have it removed for the 762 ammo. DT replaced the forward ejection port on the first warranty request and the dust cover hatch with it. With about 100 rounds thru it is still intact.

Initially the rear tear-down push pin was removed and reinserted relatively easily, but lately the pin is difficult to remove and reinstall. The rubber butt stalk and two halves of the rifle need to be squeezed and manipulated in order to reinsert the pin. I believe the issue above where a 7.62 x51 cartridge was frequently getting stuck between the ejection port and bolt carrier might have been putting outward pressure on and deforming the butt of the rifle. Nothing appears to have been done about the but of the rifle and push pin. They are still difficult to remove and reinstall and there are gaps when reassembled.

After not receiving a response from Desert Tech for several weeks I start posting my experience to a few DT related YouTube channel comment section, blogs and digital magazine comment sections I received communication from Jeff Wood of https://coldboremiracle.com/ (coldboremirakle@gmail.com). Jeff let me know that he is Desert Techs go to repair man and that he could fix it. I finally received an email from DT indicating I needed to fill out a warranty request form to generate a RMA number and receive the prepaid shipping label.

It took about a month to return to me and when I received it, the contents where in a new hard plastic case that also include a repair statement from Desert Tech. The statement indicates that a few parts were repaired or replaced and that the 25-round magazine I sent them “did not work at all” and that they “do not recommend use of 25rnd mags with the MDRx/MDR as the mags have proven to be very unreliable. The marketing flyer that comes with the rifle from DT indicates that the magazine capacity for this rifle is 10/20/30/40. The 10-round magazine is the only one that shoots reliably. The statement also indicates that Desert Tech was able to accomplish its diagnosis of “good to go” after firing only 20 rounds of S&B 147 gr. 308.

The freshly returned rifle appeared cleaned and well lubricated. Nothing was done about the factory trigger that appears prematurely warn. I replace the factory trigger with the aftermarket Jard trigger works flawlessly. The forward ejection panel that was giving the 7.62 x51 rounds so much trouble appears new and the dust cover flap is now working properly. The magazine catch latch was replace with one that does not appear to have the same poor casting as the original and did not need to be manipulated to work.

On the first trip out shooting after the rifle was returned to me I began by using 10-round magazines shooting 308 or 7.62 x51 cold. I was able to put a couple a magazine of each ammo thru it without issue. As I switch to the 20-round magazine, the gun is already heated up a bit and still on the Normal gas block setting, the 308 rounds start to jam towards the end of the clip (round 16-18). The old cartridge is ejected fine, but the new cartridge is only halfway in the chamber when the action slams closed on it. I adjusted the gas block one setting towards Advanced and then Silenced and I get the same jam. On the final Advanced setting of the gas block the 308 jam is reduced to every other clip. Switching back to 7.62 x51 20-round magazine I set the gas block to Normal and while still hot the 3rd round fired has the rim ripped off the cartridge and is left in the chamber. After removing the spent cartridge and cleaning the rifle I call it a day.

The next day I go out and buy the exact same ammo Desert Tech used to test the rifle and two new magazines, a 10 and 20. The first two 10-round magazines of 308 go smoothly and then the first 20-round magazine of 308 jams like before on round 17. On the second 20-round magazine and the 16th round in the clip the round does not discharge but instead gets stuck in the chamber with the action locked on behind it. So stuck I could not safely dislodge it or tear it down at the range. When I get home and tear it down, I discover the unspent round is the shape of a banana and was crammed into the chamber. I sent an email and pictures to Desert Tech the same day.

In the meantime, I received communication from Jeff that my riffle never made it to him, he was out of town on a hunt. Desert Tech had someone else perform the warranty work.
This is the most recently received communication from Glen Fullmer after informing him with pictures that the rifle is still not fixed and becoming more dangerous:

"Good afternoon Scott,
Please find the warranty claim form attached. If you will complete it and get it back to me, I’ll generate another RMA. Please note that if we can’t identify a defect in the rifle or duplicate the issues you’re reporting, we will charge for testing and evaluation ($50), ammunition used, and any shipping/repackaging costs. Thank you.

Glen Fullmer
Warranty Manager
Desert Tech
801-975-7272 Ext. 148
g.fullmer@deserttech.com"

I have told Desert Tech that I would prefer a refund in exchange for the return their product but they are declining to respond to that particular request. I sent the second warranty form to Glen this morning (11/5/2021). I am seeking to have a professional 3rd party evaluate the rifle before I send it back to DT.
The Gunsmith at Legendary Guns indicates the rifle is short cycling and needs to have the gas block ported as well as have some machine work done on the chamber and action. Both have sharp or jagged edges that would be attributed to ammo getting snagged or chewed up. They indicate the repairs to cost roughly $200.00