The MRDS platform supports numerous different rifle and PDW-sized builds at Zenith Firearms, from carbine-sized builds like the ZF-56 16” to PDW-style builds like the ZF-300 with a 7.5” barrel.
We’ve also configured the platform around several different rifle cartridges, each of which offers something a bit unique to modern shooters. We’ll break down the details from a high level in this post.
5.56x45mm NATO
A staple in the world of sporting rifles and one of the most commonly encountered of all short action cartridges, the 5.56x45mm NATO cartridge has a long and illustrious history of use by the United States military.
It is commonly loaded with a bullet between 55 and 70 grains (though lighter and heavier loads are available) and produces muzzle energies usually in the range of 1270 to 1460 ft-lbs, but again this is determined by load data.
Some Selling Points of the Cartridge
There are many selling points of a 5.56x45mm NATO chambering. Among them are the following.
- 5.56 ammo is low-cost and readily available.
- Bulk and surplus deals are available that drive down the cost further.
- Many different types of loads are available.
- It produces little recoil, making it effective for smaller-framed shooters and beginners.
- 5.56 is a flat-shooter, making it effective for long-range shooting.
- It has numerous applications such as sport shooting and hunting small and medium game.
7.62x39mm Soviet
The 7.62 Soviet cartridge is an older cartridge with nearly 100 years of history. This is the infamous cartridge around which both the SKS and AK-47 were built.
It produces more stopping power than 5.56 NATO, but it doesn’t perform well past 100 yards or so and has a terribly dropping trajectory. It’s typically loaded with a bullet weighing between 123 and 255 grains, producing muzzle energies ranging from 1400 to more than 1700 ft-lbs.
Why 7.62 Soviet?
Let’s take a closer look at some of the reasons an MRDS platform chambered in 7.62 might be a good choice for you.
- Like 5.56, 7.62 is low-cost and generally widely available.
- There are also bulk deals that can drive down the price.
- 7.62 offers better stopping power than 5.56.
- It performs fairly well from a shorter barrel.
With that said, it’s also important to recognize the limitations of 7.62 Soviet, the primary one being the fact that it does not perform well at extended ranges.
.300 Blackout (AKA .300 BLK)
The .300 Blackout is like a beefed up 5.56 that performs well at closer ranges and which delivers more stopping power. It also performs very well from a shorter barrel.
Typically loaded with a bullet weighing between 110 and 220 grains, producing muzzle velocities in the area of 1100 to 1350 ft-lbs. There are also subsonic loads that produce much lower muzzle velocities closer to 500 ft-lbs.
Value Drivers in .300 BLK
There are some good reasons to consider an MRDS platform chambered in .300 BLK. Here are some of the best of them.
- .300 BLK produces greater stopping power than 5.56, but rifles chambered in .300 BLK often use many parts that are cross-compatible with their 5.56 counterparts.
- You can reload old 5.56 casings with .300 if you have the appropriate equipment.
- The .300 BLK cartridge performs very well suppressed and even better from a short barrel, making it excellent for ARP builds. It can achieve complete powder deflagration in a barrel as short as 9”.
With that said, it is important to note that .300 BLK is more expensive than 5.56, harder to find, produces more recoil, and performs abysmally at long ranges.
.350 Legend
Here we should also consider the .350 Legend, a straight-walled rifle cartridge that was primarily developed in response to states that have passed legislation requiring straight-wall cartridges for deer hunting.
As a sporting cartridge, the .350 Legend definitely has its applications. It’s typically loaded with a bullet between 124 and 180 grains, producing muzzle energies between roughly 1700 and 2100 ft-lbs, making it the most powerful cartridge on this list, which makes sense since it was specifically designed to dispatch deer and other similarly sized game.
Where the .350 Legend Makes Sense
First and foremost, the .350 Legend was designed for hunting, but here are some good use cases:
- Despite the relatively high cost and relative rarity, it’s compliant with some laws in states that require straight-wall cartridges for deer hunting.
- In terms of sheer power, it generally outperforms the other cartridges on this list.
Ultimately, the .350 Legend doesn’t make sense for sport shooting, but if you are a hunter and need a hard-hitting straight-walled cartridge that doesn’t kick like .45-70 Gov’t., this is a great choice.
Want to Learn More About the MRDS Platform?
If you’re still weighing your options and aren’t sure what cartridge you want, or what barrel length makes the most sense for you, check out the MRDS platform in depth via the previous link. You can also get in touch with us directly if you have any questions and we will help you out.