In case you didn’t know, 300 Blackout-chambered AR-15s are technically a few guns in one. Yes, 300 Blackout was designed to be one of the most versatile and multi-functional rounds ever. The military wanted a weapon platform that could shoot long, short, quiet, and loud – all without making any modifications to the weapon itself. But owning a 300 Blackout rifle or pistol means investing in the right barrel – it matters so much more here compared to the average .223, 5.56, or .308 AR. Let’s go over the 3 best 300 Blackout barrels and what to look for, depending on your build:
- 16” Stainless, M4 Profile 300 Blackout Barrel
The 16” barrel is still the gold standard for the 300 Blackout rifle, and we don’t dispute it. At this length, you’re getting the most velocity you’ll need for accurate medium-range shooting. What’s more, the 416R stainless steel this barrel’s made from provides the most precise and hardened rifling you’ll find in any stainless barrel.
Coupled with a heat-treating process that brings the steel’s hardness to a rating of RC 28 to 32, this 16” SS 300 Blackout barrel will be the one to beat if you want the most accuracy possible from the 300 Blackout cartridge. We recommend this barrel for the bench shooter or hog hunter on the prowl.
It comes threaded for a can of your choice, and features a carbine length gas system that guarantees reliable cycling with suppressed and unsuppressed loads, super or sub.
- 16” Heavy Spiral Fluted 300 Blackout Barrel
If you’re in the market for building one of the most rugged, toughest, and most badass 300 Blackout rifles imaginable, you’ve found the right barrel. Featuring a heavy profile and made from top-of-the-line 4150 Chromoly steel, this barrel can handle sustained, rapid fire even with suppressed loads.
The included fluting reduces weight, ensuring your 300 Blackout rifle is still ergonomic and comfortable. Fluting also stiffens the barrel to improve accuracy. Coupled with CNC cut rifling and that same heat treatment process to bring the steel hardness to RC 28 to 32, this is going to be one of the most reliable and long-lasting 300 Blackout barrels available on the market.
It will average sub-MOA accuracy at 100 meters, and its parkerized finish and 4150 Chromoly steel are 100% mil-spec.
- 10.5” Heavy 4150 Chromoly 300 Blackout Barrel
Last, but by no means least, we present our 10.5” gold standard barrel. In our humble opinion, this little barrel represents everything the 300 Blackout was meant to be. At 10.5”, this sub-rifle-length barrel maximizes accuracy with the shortest, lightest, and most functional build possible.
Popular opinion agrees that 10.5” is the true sweet spot if you want a 300 Blackout gun that’s compact, accurate, and guaranteed to cycle super and sub loads, suppressed or unsuppressed. This barrel’s heavy profile, CNC cut rifling, and heat-treating process make it the barrel to beat. Weighing just 1.7 pounds, it’ll be the perfect choice for the shooter who wants to build the perfect SBR or 300 Blackout pistol from scratch with an 80 lower.DISCLAIMER: If you are new to the world of DIY gun building, you likely have a lot of questions and rightfully so. It’s an area that has a lot of questions that, without the correct answers, could have some serious implications. At 80 Lowers, we are by no means providing this content on our website to serve as legal advice or legal counsel. We encourage each and every builder to perform their own research around their respective State laws as well as educating themselves on the Federal laws. When performing your own research, please be sure that you are getting your information from a reliable source.