Guest Post: Pros and Cons of the .350 Legend cartridge

by George Groot

George is a member of our Facebook Group and has written for us before.

The AR-15 platform has a number of cartridge options other than the 5.56x45mm/.223 Remington option: .300 BLK, 6.5mm Grendel, 6.8mm SPC, 7.62x39mm, and as far as I know the now-defunct Olympic Arms crammed the entire family of Winchester Super Short Magnums into the rifle . Every single one of these options is superior to the 5.56 in some way, but generally inferior when it comes to price and parts compatibility.

Of all the other options, only the .300 BLK and 7.62x39 enjoyed some sort of widespread adoption, the others remaining niche builds for niche people. The 7.62x39 builds lack bolt face standardization, but other than that it benefits from reasonably-priced import ammunition for plinking.

The reason that the .300 Blackout is so widely adopted is that it does a few things well:

• The only difference from an AR in 5.56 is the barrel; all other parts are the same, which makes it a cheap buy or build. 
• The brass can be made from cheap surplus 5.56, and manufactures can make .300 Blackout from the same manufacturing line as normal 5.56. 
• Hunting laws in some states require a .24 cal/6mm or larger cartridge for hunting anything but varmints. 

So the lesson to be learned from this is that price is probably the number one factor in widespread adoption of a non-5.56 option for an AR-15 pattern rifle.

Pluses and Minuses
This brings us to the .350 Legend cartridge. It has all of the same advantages as .300 BLK  (with one caveat about magazines), but does so with a larger bullet which is better suited to hunting large game and is hunting legal in states that require “straight wall” center fire cartridges. The .350 Legend equals the energy and ballistics of the venerable .30-30 quite nicely, but from a 4” shorter barrel. The relatively slow 1:16 twist rate is well suited to even cast bullets at full velocity from the cartridge.

The downside is the aforementioned caveat about magazines. Standard milspec 5.56x45 magazines will not work with the .350 Legend, and must be modified. There are plenty of YouTube videos on how to do this, but needing to split your stock of magazines between 5.56 and .350 Legend could be a deal breaker for some. However, for hunting a 5-round commercial magazine is all you’ll need for anything antlered, and for hunting feral hogs modifying a few 30-round magazines would likely be the least expensive part of any given hunting trip.

Interesting Points
I prefer the .350 Legend to the .300 BLK because it eliminates the possibility of using the wrong cartridge with the wrong barrel. Some folks have messed up and fired a .300 BLK in a 5.56 chamber, with predictably catastrophic results; others are careful to mark magazines and ensure proper ammunition segregation so that mismatches don’t happen. However, due to cartridge length, you cannot load a .350 Legend into a 5.56/.223 chamber.

It remains to be seen whether or not the .350 Legend goes on to more widespread commercial adoption, or falls into a “niche” like the .35 Whelen, .358 Winchester, and .35 Remington before it. The .35/9mm bore has not been a hit with American sportsman over the .30 caliber options of .30-06, .308 Win, and .30-30 Win (the  direct competitor of .35 Rem in the lever gun market).

However, people who own, shoot, and hunt with the .35 caliber family have been quietly keeping it alive and in the American market for decades now, so there is always the possibility of a broader adoption of the .350 Legend. Even if there is not widespread adoption, ammunition is easily crafted from readily available components. For a hunter, less than 200 rounds a year would be sufficient for nearly anything that requires a tag, and easily assembled over a weekend.

If you already have a .30-30 lever rifle, there is no need to go out and purchase the parts to assemble a .350 Legend unless you just want to, because ‘Murica. But, if you happen to find yourself in the market for a lightweight, ergonomic carbine for hunting, the .350 Legend is a great option to fill that niche from a ballistics standpoint if you handload or don’t mind paying for commercial ammo.