A large number of sporting rifles (not just AR-15s and clones) are chambered in 5.56, if not an outright majority.
It is a low-cost, ubiquitous caliber that shoots flat, produces little recoil, and which has a ton of use cases, from hunting to sport shooting and even some defense applications.
But 5.56 is only one of many rifle cartridges out there that make excellent chamberings for a sporting rifle. One great alternative is .300 Blackout, also known as .300 BLK, which, though it is more expensive than 5.56, offers some considerable advantages, especially in a platform such as the ZF-300.
Here’s what you should know.
The MRDS Platform
First, the ZF-300, unlike so many sporting rifles, is built around Zenith Firearms’ MRDS platform, which is a roller-delayed blowback system, instead of the gas impingement systems that many modern sporting rifles use.
The MRDS platform, being roller-delayed, is not only smooth-shooting and well-suited to suppression, it is simpler by nature than gas impingement systems, which in turn makes it not only more reliable, but longer-lasting.
There are fewer parts to tune; there’s no gas system or buffer system, which latter point in and of itself is also a selling point, since the rifle can be made even more compact without a buffer tube protruding from the receiver.
Stopping Power
The cartridge itself is another thing to love about the ZF-300. The .300 Blackout cartridge fires a larger, heavier bullet than 5.56, producing not only a wider wound channel but more stopping power overall.
Loaded with an appropriate bullet, the .300 BLK cartridge can be much more effective than 5.56 for defensive applications, and some even prefer it for predator control or for taking furbearers for the same reason.
The one caveat is that it does not perform well at ranges in excess of a few hundred yards, as the trajectory is badly drooping and the round loses power pretty quickly.
Better Performance from a Short Barrel
The 5.56 might shoot fast and flat, but that comes at a price and it does not do well from a short barrel. You can build a micro ARP with a short barrel, but if it’s chambered in 5.56, you will not only get a lot of muzzle pop, but you will deal with a lot of fouling.
The .300 BLK performs optimally out of barrels even shorter than 10 inches, and even from a short barrel, the cartridge has plenty of time to fully deflagrate the propellant charge, resulting in less muzzle pop and potentially less fouling.
But you don’t need to worry about the details; what matters here is that if you want a short barreled build, .300 BLK has a lot of advantages in this capacity over 5.56.
Better Performance Suppressed
The MRDS platform around which the ZF-300 is built also responds better to the higher pressures associated with suppression than gas systems do, and on top of that, .300 BLK in general performs well from suppressors.
There are also subsonic .300 BLK rounds that you can investigate that you can shoot through a suppressed platform that will perform well at close ranges and which will produce a shockingly quiet report.
Where to Learn More About the ZF-300 MRDS Platform in General
Thinking a ZF-300 (or some other rifle built around the MRDS platform) might be for you? You can learn more at Zenith Firearms or get in touch with them directly at Info@ZenithFirearms.com or at 434-202-7790 and they will be ready to assist.
