The new 300 Blackout MDRX

The new 300blk conversion kits have been shipping out starting in January 2023, lots of customers have been telling us their experiences with the new kit, and today I we wanted to share one of those experiences with you.

This story comes from a customer named Lawrence, I’ll let him tell you the story.

” I may not be like most MDRX owners; what initially drew me to the MDRX was the idea of running it in 300blk. Granted, I much appreciate the quick caliber change abilities of the rifle and intend to make good use of the 223 Wylde and 308 Win kits, but what fueled my impulse purchase was the 300blk chambering.

Much to my dismay, production of the 300blk kits was put on hold when I originally made my purchase, so I patiently waited while familiarizing myself with the intricacies of the platform in the aforementioned calibers. When the 300blk kits were re-released, I managed to get ahold of one and get it installed.

The only somewhat difficult part was swapping the recoil spring, Everything else was standard operating procedure for a MDRx caliber swap.”

The addition of a shorter operating spring for the 300blk was essential to ensure proper cycling for both supersonic and subsonic ammunition. We certainly wanted customers to be able to take full advantage of the 300blk and its qualities, so ensuring that operation was key to the new design.

“I added a Vortex Strike Eagle 1-8x LVPO and a Silencerco Omega 300 Suppressor and decided to test it out. I used Ammo Inc 110gr V-Max for supersonic groups and Gemtech 187gr for subsonic groups. Supersonics were shot at gas setting #1, and subs at setting #4. I had no malfunctions of any kind, and the rifle was pleasant to shoot with very little recoil. Surprisingly, I had very little gas blowback when shooting suppressed as well. “

Me again; I wanted to take the opportunity to explain the importance of ensuring the proper gas setting is used with the 300blk MDRX. In order to be compatible with both subsonic and supersonic ammunition, it required significant gas port size to ensure there was enough to operate the rifle with subsonic ammunition. With such a large gas port, it could cause irreparable damage to the rifle if used with the higher pressure supersonic ammunition.

Make sure to follow the included directions with your 300blk conversion kit to ensure you use the proper gas setting to avoid this damage. The safest direction I always recommend is to use the lowest setting that will reliably operate the rifle.

The 300blk is not thought of by many as an extremely accurate round; it is intended for close to medium range work. That being said, accuracy at 100 yards proved to be more than adequate, with most groups averaging 1.5 moa. I believe this could be tightened substantially by running better quality ammo.

Subsonics grouped a bit wider, but I have not had much luck with this particular subsonic ammo in other platforms either. I definitely plan to get better subs to test in the near future to see what the rifle is fully capable of.

I have thoroughly enjoyed shooting the 300blk kit. I have about 100 rounds down the pipe and look forward to seeing how it behaves with extended use. I will keep you guys informed as time progresses.

We look forward to hearing from Lawrence and other customers about their experiences with the 300blk and any other Desert Tech products. Comment below to tell us about your experience.

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