Straight-wall rifle cartridges are getting big play in hunting circles this year, and Rock River Arms has delivered an AR-platform chambered for this exciting new round

by Rob Reaser

For true fans and students of the gun, we certainly live in a time when many among us may not fully appreciate the incredible diversity of firearms and ammunition at our disposal. This is not due to any sort of apathy or ingratitude, but more a result of limited perspective.

When I formed my frame of reference for hunting rifles in the early 1980s, there was something of a generational overlap going on. Guys from my grandpa’s era (at least in my area of the Appalachians) seemed to cling to the classical deer rifle forms, led prominently by the Winchester model 94 lever action. This was often the first rifle stuck into the tender hands of my generation, being readily available, easy for a youth to carry, and familiar territory to operate since all of us had plenty of muscle memory built-in from our childhood adventures with Red Rider BB guns.

Those of our fathers’ generation, on the other hand, usually gravitated toward bolt action hunting rifles of the Remington 700 or Winchester model 70 flavor. As young hunters, those were the rifles we aspired to own as soon as our apprenticeship time was up working with the hand-me-down lever actions.

Flash forward to today. The last couple decades have seen a veritable explosion of new, modified, and hybrid platforms designed to meet just about any objective you can think of that involves propelling a projectile downrange. Sometimes, the innovation has been led by the firearm, sometimes by ballistics requirements, sometimes to fill a specific niche that ends up having wider application and acceptance beyond its original intent.

The .350 Legend cartridge introduced in 2019 falls under the latter.

For years, deer hunters in certain states and areas were limited in their firearm options due to regulations curtailing the use of “high-powered” centerfire rifle cartridges. The general idea was that high-velocity ammunition was deemed incompatible, for safety reasons, in areas of flat terrain and denser populations. Here, deer hunters were often restricted to using shotguns, muzzleloaders, or handguns chambered for straight-wall pistol cartridges.

That changed several years ago when Michigan decided to allow the use of straight-wall cartridges in .35 caliber or larger with case lengths ranging from 1.16- (minimum) to 1.80-inch (maximum). Winchester seized this opportunity to develop an entirely new cartridge that would fall within these parameters while utilizing manufacturing efficiencies to keep production costs down.

Enter the .350 Legend.

The .350 Legend offers a totally new cartridge case (not based on a parent case) that features the same rim diameter as the .223 Rem, allowing Winchester to employ existing equipment and some processes to control manufacturing costs. The case length hits the 1.71-inch mark with an overall cartridge length of 2.26 inches. The published bullet diameter for the .350 Legend is .357 inches.

While dimensional specs play to the geek intrigue, the real value of the .350 Legend is its ballistic performance and shooter experience. Winchester touts the .350 Legend as, “The World’s fastest straight-wall hunting cartridge,” with energy exceeding that of the .30-30 Win, .300 BLK, and .223 Rem and 20% more penetration than the .243 Win. As for recoil, the .350 Legend cannot help but to be compared to its more famous straight-wall cartridge bruiser, the .450 Bushmaster. Winchester’s data reveals the .350 Legend’s felt recoil to be more than half that of the .450 Bushmaster. Having shot both cartridges in AR platform rifles, we must agree.

One of the challenges of introducing an all-new cartridge is getting rifle manufacturers to chamber for the new round. Several have stepped up to the .350 Legend plate, and one of the most recent is Rock River Arms.

RRA offers two AR-platform rifles chambered in .350 Legend—black phosphate or stainless-steel barrels. Billed as the LAR-15M, these rifles are familiar RRA fare, featuring the company’s forged A4 upper and multi-caliber lower receivers, 13-inch extended free-float handguard, Operator CAR stock, and two-stage trigger.

Given that the .350 Legend cartridge is intended for hunting applications out to 250 yards, the LAR-15M is ideally suited to the task. The 16-inch barrel is certainly maneuverable in the brush, and with its 6.8-lb. weight, the rifle is an easy carry when outfitted with a quality sling. The included magazine, which is specific to the .350 Legend, boasts a 10-round capacity.

A few other features that lend the LAR-15M to hunting include the winter trigger guard, making the trigger more accessible when wearing cold-weather gloves; the Operator CAR stock, with its generous cheek weld and length-of-pull adjustability to accommodate clothing layers; and the overmolded A2 grip. The overmold means minimal hand-slip when wearing gloves, and it makes the A2 grip more comfortable when shooting bare-handed.

The handguard is RRA’s own design, and I like it for its smooth simplicity. Being M-LOK compatible, you can fit whatever railed accessories you like or keep it clean.

Leading the charge is RRA’s Operator muzzle brake. It’s an aggressive little thing that, should you run out of ammo to fend off a charging beast, could be turned into a defensive tool in its own right.

I acquired Federal and Hornady cartridges for the range test. After installing and zeroing a TRUGLO Omnia 8—a suitable optic for this firearm platform—I set up for ballistic and group size evaluation. The results:

Federal Non-Typical, 180-gr. soft point; 5-shot string #1

  • Muzzle Velocity: 2149.4 fps (ave.)
  • Kinetic Energy: 1845.6 ft/lbs
  • Standard Deviation: 11.44 fps
  • Extreme Spread: 24.5 fps

Federal Non-Typical, 180-gr. soft point; 5-shot string #2

  • Muzzle Velocity: 2158.4 fps (ave.)
  • Kinetic Energy: 1861 ft/lbs
  • Standard Deviation: 21.06 fps
  • Extreme Spread: 55.97 fps

Hornady American Whitetail, 170-gr. InterLock; 5-shot string #1

  • Muzzle Velocity: 2152 fps (ave.)
  • Kinetic Energy: 1747.6 ft/lbs
  • Standard Deviation: 11.5 fps
  • Extreme Spread: 27.01 fps

Hornady American Whitetail, 170-gr. InterLock; 5-shot string #2

  • Muzzle Velocity: 2129.2 fps (ave.)
  • Kinetic Energy: 1711 ft/lbs
  • Standard Deviation: 17.71 fps
  • Extreme Spread: 40.52 fps

Last year, I got to spend some time with a pre-production version of the LAR-15M and managed to shoot sub-MOA groups. My best group this go-around was 1.443 inches. Knowing first-hand the accuracy reputation of RRA rifles through many we’ve tested for Shoot On and looking at the ballistic performance of the two cartridges tested for this evaluation, I must conclude that neither load hit this particular LAR-15’s sweet spot, although the Hornady American Whitetail’s performance would absolutely get the job done. More load testing is definitely on the menu.

Interestingly, while testing the LAR-15M, a guy set up on the bench next to me and pulled out a youth model Savage bolt-action. He asked what I was shooting, and then said, “Well, that’s funny. This is a .350 Legend.” Turned out, he had just bought that rifle for deer hunting and got a youth version because it was the only one in stock. Ammunition for the .350 Legend was available, but he couldn’t find anything for his .270. Which brings me to my point.

There will probably be a slew of hunters this year who end up walking out of their go-to sporting goods retailer with empty hands and long faces because their standard ammo is not to be had. Aside from being a superb cartridge for deer, hogs, and bear, the .350 Legend and rifles so-chambered, such as the Rock River Arms LAR-15M, may be among the few firearm/ammo matchups in stock this season…at least for the next month or so. As I write this, a quick Internet search reveals .350 Legend is among the few cartridges still available from online retailers.

Our advice…make your decision and your move now.

Shoot On Editor-in-Chief Rob Reaser is a lifelong outdoorsman, former magazine editor, columnist, and contributing editor to numerous national publications in the automotive and outdoor segments. He has also authored and co-authored several DIY gun building books. His shooting and hunting passions cover everything from traditional archery and big-game bowhunting to the latest in handguns, rifles, and reloading. Rob has a troublesome habit of pulling guns and things apart to see how they work; occasionally, he manages to get them back together...

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