The Best AR-15 Hunting Rounds for Hunting

With the appropriate cartridges and bullets, AR-15-style rifles are suitable for a variety of hunting pursuits.

December 24, 2025 By Richard Mann

Veterans have always driven the popularity of hunting rifles. World War I veterans moved us away from the lever gun toward the bolt action while also cementing the legend of the .30-06. After World War II and Korea, semi-auto rifles like Remington’s Model 742 and Winchester’s Model 100 were wildly popular. The AR-15 flourished after the recent Middle East conflicts, especially as the platform’s modularity grew. Thus, for the past several decades, we’ve seen many new AR-15-compatible cartridges introduced, and all of them have hunting applications.

With more than a dozen such cartridges, hunters wanting to use a modern sporting rifle have many choices. Maybe the best way to select one is to think of the end purpose. There are four basic applications to consider: recreational shooting, varmint/predator hunting, deer-sized game and game larger than deer. Some states also mandate straight-walled cartridges for deer hunting, and there are three proven AR-15-compatible rounds that meet that requirement.

PLINKER’S DELIGHT

If you’re mostly interested in recreational shooting, the .223 Remington/5.56 NATO is the clear choice. These are the most popular AR-15 chamberings, and the platform was originally designed to use them. There are nearly 200 factory loads, including some of the least expensive AR ammunition available. With the AR-15’s modularity and the sub-5-foot-pounds of recoil the .223 and 5.56 generate, they’re great for new and young shooters.

However, there is a difference between the .223 Rem. and 5.56 NATO. Externally, the cartridges are dimensionally identical, but the 5.56 NATO operates at higher pressures. It’s safe to shoot .223 ammo out of a 5.56 rifle, but not the reverse. The best solution is a rifle with what’s called a “.223 Wylde” chamber, because it will safely and accurately shoot both .223 Rem. and 5.56 NATO ammo.

VARMINT SLAYERS

Although about half the AR-15 cartridges available are fine for hunting varmints and predators, the .223/5.56 is once again a great choice due to availability and cost. This is especially true for smaller varmints, like prairie dogs, where you might shoot a lot in a day. For a dedicated predator rifle, some of the more powerful AR-15-compatible .22 centerfires, like the .22 Nosler, .224 Valkyrie, .22 ARC and even the 6mm ARC, offer more reach. However, the ballistic performance of all these cartridges out to around 350 yards is so similar, the availability and light recoil of the .223/5.56 is hard to beat.

MEDIUM-GAME GEMS

Though some hunters claim it’s not enough gun, the .223/5.56 will work for deer and feral hog hunting. Over the years, I’ve taken about two dozen deer with the .223 Remington, and it has worked marvelously. The key—as with any cartridge—is to choose the right bullet. The 62-grain Federal Fusion load, the 70-grain Nosler AccuBond load and the 75-grain Swift Scirocco load are all ideal. However, currently the .223/5.56 is only legal for deer hunting in 36 states. This caliber limitation also applies to other AR-15-compatible .22 centerfires.

I think the three best cartridges for medium-game applications are the 6mm ARC, 6.5 Grendel and .300 HAMR. You can view 6mm ARC and 6.5 Grendel as sort of light versions of the .243 Winchester and 6.5 Creedmoor. With both, bullets will weigh 130 grains or less, but their high ballistic coefficients allow them to retain velocity and energy well and shoot reasonably flat out to 300 yards.

One of the most trusted deer cartridges ever is the .30-30 Winchester, and the .300 HAMR cartridge duplicates, and in some cases exceeds, its performance. The other advantage of the .300 HAMR is that it’s based on the .223 Remington case. This means more magazine capacity and better durability than you’ll find with the 6mm ARC and 6.5 Grendel, which require a larger bolt face.

BIG-GAME PINCH HITTERS

Once you’re after game larger than deer, AR-15 cartridges lose appeal, mostly because they’re limited in power due to the powder capacity of the smaller cases. The 6.5 Grendel’s bullet diameter is the same as the 6.5 Creedmoor, but given similar bullet weights, the 6.5 Creedmoor has about a 250 feet per second (fps) edge. The same is true when comparing the 6mm ARC to the .243 Winchester. And because the .300 HAMR case has even less capacity, the .308 Winchester has about a 500 fps advantage over it.

These three AR-15 cartridges can work on bigger game, and are probably the three best options, but they aren’t necessarily ideal. Compared to more conventional big-game rounds compatible with the larger and heavier AR-10, their reach is limited.

STRAIGHT-WALL STOPPERS

There are three straight-walled cartridge options in the AR-15. The first and oldest is the .450 Bushmaster, which hits harder at 100 yards than any other SAAMI-approved AR-15 cartridge. But, it also recoils substantially more, and at 300 yards, bullets drop about 3 feet.

The .350 Legend has been the most successful and has even found appeal with deer hunters outside straight-wall states. It’s also popular as a youth cartridge for deer because recoil is still mild. Comparing trajectory, terminal performance and recoil, it might be the best all-round straight-wall option.

The best AR-15 cartridge might just be any of them. This is because, with the platform’s modularity, you can swap upper receivers, switching between cartridges in seconds. This is done most easily with cartridges of the same bolt-face diameter, like .223 Remington, .300 Blackout, .300 HAMR and .350 Legend. But, if you also change the bolt when switching uppers, you can shoot all compatible cartridges with one rifle. This is what makes the AR-15 one of the most versatile rifles ever made. You can have one rifle for every task, even personal protection.