300 Blackout is awesome for hunting. Want to stalk wild boar? Easy. You can make your rifle so quiet, the only sound you’ll hear when you squeeze the trigger is the bolt cycling – that’s with subsonic. Shoot supersonic and stay within 150 yards (the distance that 96% of all hunters take their shots) and you’ll be able to drop a deer or elk with ease.
But hunting with an AR 15 requires the right setup. Perfecting that setup becomes even more important if you want a gun that’ll reliably, accurately shoot suppressed or unsuppressed – remember, we’re working with loads raining from 120 grains up to 220 and more.
Best Barrel Length for Hunting with 300 BLK
Thankfully, we have just the setup for you. But before we get to anything else, let’s clear something up: Longer barrels do not equal more accuracy. Longer barrels only provide more velocity, but every round has its optimal velocity and barrel length. This misconception about barrel length and accuracy has managed to live too long in the AR world, thanks to the ballistics of the standard 5.56 NATO cartridge.
Why? Because most AR 15s are built using 16” barrels, but the 5.56 optimal barrel length is 20”. That’s because the original M16 featured a 20” barrel – that’s the length that gets 5.56 moving as fast as it’ll ever go.
But how much barrel is needed to get 300 BLK trucking along at terminal velocity? Only meager 9”. That’s right, it’s over half the required length. Same gun otherwise, by appearance and function – wildly different requirements.
That means you can hogs and four-legged creatures using a more compact rifle. If you don’t want to deal with the NFA paperwork of building an SBR, we recommend the minimum barrel length of 16”.
You’ll also want to stick with a pistol- or carbine-length gas system. These two systems are the only lengths capable of cycling supersonic and subsonic munitions, suppressed or unsuppressed.
The Best Twist Rate is…
Simply put, the best twist rate for hunting with 300 BLK is 1:7 or 1:8. If you plan to shoot heavier, subsonic rounds more for those juicy, mean hogs, then the “faster” 1:7 is best. If you want to drop deer or elk at greater distances with lighter supersonic loads, 1:8 will do you just fine.
If your rifle’s going to be dedicated to shooting supersonic loads, you could go with a 1:10 twist rate. But the return on the investment is minimal compared to 1:8. You’ll also sacrifice some much-needed stability if you ever do decide to shoot subsonic.
Picking the Right Barrel Steel
We’ll keep this simple once again: Stainless is inherently more accurate than chromoly steel barrels. Why? Because the steel that should be used in barrel building – 416R Stainless, the stuff we use – provides the best machinability to create the most precise rifling. It also suffers fewer ferrous and non-metallic properties, like sulfur, which can shorten barrel life and rifling precision.
That’s not to say a high-quality 4150 Chromoly barrel won’t be accurate. Our customers frequently comment on their ability to achieve 1 MOA accuracy at 100 yards – with our 416R stainless barrels, that number drops down to around 0.7 MOA, or less than 1” groupings at 100 yards.
All Other Components Considered
Your barrel length and steel, twist rate, and gas system are the three critical components needed to build the ultimate 300 BLK hunting rifle. You’ll also want to invest in some flip-up front and rear sights (we particularly like Magpul’s BUIS system for its cost and quality).
With this configuration we also recommend sticking with your typical adjustable buttstock – none of those large, fixed, heavy stocks are necessary at the distances you’ll be hunting. They add weight and bulk, and generally hinder the whole purpose of the ultimate 300 BLK hunting rifle: To function as a lightweight, compact, accurate weapon out to 200 yards.
The Lower Counts, Too
Picking a good, quality lower with a smooth trigger system is the final key in unlocking the perfect 300 BLK hunting rifle. Our premium lower parts kit offers that crisp single-stage trigger you're looking for. It affords little to no takeup, overtravel, or creep, and it's tuned to a Goldilocks 4.5 pound pull.