The .223 Remington and its military sibling, the 5.56 NATO, are versatile, popular, and effective for numerous sports. But shooters, being restless by nature, eventually want an alternative. They search for something faster, more powerful, or just plain different.
Two alternatives are the 6.5 Grendel and the .300 AAC Blackout.
Both are fired from the AR platform, but this is (essentially) where the similarities end. Choosing the right one for your needs starts with an understanding of each round’s performance and market conditions.
Let’s compare the 6.5 Grendel vs .300 Blackout to discover which is right for you.
Making the Choice: 6.5 Grendel or .300 AAC Blackout?
We’ll get into detailed stats below and after seeing them, you may assume that the 6.5 Grendel is simply “better.” It’s not better, it’s different. Although the .300 BLK is slower, less powerful, and has significant drop at 500 yards, there are clear advantages to each cartridge.
Advantages of the 6.5 Grendel:
- More speed and higher energies from muzzle to target
- Far superior downrange trajectories
- The better option for long-range shooting
- A viable deer-hunting option for shots of 300 yards or more
Advantages of the .300 AAC Blackout:
- More ammo options available to shooters
- Suppressed shooting available
- Wider bullet creates larger wound channels
- With slower velocities, it’s a better option for home defense
- Lower muzzle energies generally translate to lighter recoil
6.5 Grendel vs .300 Blackout – Specs
6.5 Grendel | .300 AAC Blackout | |
Bullet Diameter | 0.264 inches | .308 inches |
Neck Diameter | 0.293 inches | .334 inches |
Base Diameter | 0.439 inches | .376 inches |
Case Length | 1.52 inches | 1.368 inches |
Case Capacity | 0.1514 cubic inches | 0.0913 cubic inches |
Overall Length | 2.26 inches | 2.26 inches |
Typical Bullet Weights | 90 - 130 grains | 90 - 220 grains |
Typical Firearm | AR-15 semiautomatic rifles | AR-15 semiautomatic rifles |
What’s the Same?
Despite the obvious differences (which we’ll discuss later), there are some similarities between these rounds. First, as we have already addressed, they are both made for the ever-popular AR platform. AR-15 users can transition to either of these cartridges with simple changes to their rifles. They can enjoy different performance profiles while maintaining the versatility and ease of use that has made the AR popular.
But there is another interesting similarity: they both have an overall length of 2.26 inches. You may assume that this would mean similar performance but (spoiler alert), these rounds have vastly different speeds, energies, and trajectories.
Physical Differences
Other than overall length, the two rounds are different in almost every measurement. The Blackout’s bullet is wider, but the case length and base diameter are less. This translates into a smaller case capacity.
The bullet weights mostly overlap, but the Blackout goes a bit heavier, topping out around 150 grains for commonly-available rounds. It also has bullets as heavy as 220 grains, but these are made for subsonic shooting.
The Market: Pricing and Availability
Neither of these cartridges are rare, but owners of a .300 AAC Blackout rifle will have an easier time finding ammunition. For example, when we wrote this article we had 40 different 300 Blackout ammo options for sale on our website. You could find a cheap 300 Blackout option at about half the price of the cheapest 6.5 Grendel available. On the other side, we only had about 15 options for 6.5 Grendel ammunition in-stock.
Sourcing ammo, a common concern in today’s market, is easier and more affordable with the Blackout.
6.5 Grendel vs .300 BLK: Ballistic Performance
To analyze the velocity, energy, and trajectory of these two cartridges, we selected five rounds that span the range of weights. For the Grendel, the rounds ranges from 90 to 130 grains, while the Blackout’s sample included 110 to 150 grain weights.
This sample, however limited, helps us understand the performance potential for each of these rounds…
Velocity
6.5 Grendel | Muzzle (fps) | 100 | 200 | 300 | 400 | 500 |
90-grain Varmageddon(Nosler) | 2,800 | 2,549 | 2,311 | 2,086 | 1,874 | 1,677 |
100-grainELD-VT V-Match(Hornady) | 2,730 | 2,531 | 2,340 | 2,158 | 1,984 | 1,819 |
115-grain TAC-TX BT(Barnes) | 2,590 | 2,367 | 2,155 | 1,954 | 1,765 | 1,590 |
120-grainFusion MSR(Federal) | 2,600 | 2,346 | 2,107 | 1,881 | 1,674 | 1,485 |
130-grain Premier Match(Remington) | 2,400 | 2,251 | 2,108 | 1,969 | 1,836 | 1,711 |
AVERAGE | 2,624 | 2,409 | 2,204 | 2,010 | 1,827 | 1,656 |
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.300 AAC BLK | Muzzle (fps) | 100 | 200 | 300 | 400 | 500 |
110-grain Varmaggeddon(Nosler) | 2,200 | 1,930 | 1,681 | 1,460 | 1,273 | 1,130 |
120-grain Power-Shok(Federal) | 2,100 | 1,799 | 1,533 | 1,307 | 1,136 | 1,024 |
120-grain VOR-TX(Barnes) | 2,100 | 1887, | 1,688 | 1,507 | 1,347 | N/A |
125-grainPremier Match(Remington) | 2,215 | 1,977 | 1,755 | 1,553 | 1,373 | 1,224 |
150-grainPower-Shok JSP(Federal) | 1,900 | 1,685 | 1,490 | 1,320 | 1,181 | 1,079 |
AVERAGE | 2,103 | 1,848 | 1,629 | 1,429 | 1,262 | 1,114 |
The 6.5 Grendel holds a clear velocity advantage. The difference, based on averages from muzzle to 500 yards, is about 550 fps. Even the slowest 6.5 Grendel outruns the fastest .300 AAC Blackout.
At 500 yards, the 6.5 Grendel is cruising at an average speed of 1,656 fps while the Blackout averages just over 1,100. This suggests that the Blackout will soon lose its ballistic stability and begin to wobble long before the Grendel.
Energy
6.5 Grendel | Muzzle (ft-lbs) | 100 | 200 | 300 | 400 | 500 |
90-grain Varmageddon(Nosler) | 1,567 | 1,298 | 1,067 | 869 | 702 | 562 |
100-grainELD-VT V-Match(Hornady) | 1,655 | 1,422 | 1,216 | 1,034 | 874 | 735 |
115-grain TAC-TX BT(Barnes) | 1,713 | 1,431 | 1,186 | 975 | 796 | 646 |
120-grainFusion MSR(Federal) | 1,801 | 1,467 | 1,183 | 943 | 747 | 588 |
130-grain Premier Match(Remington) | 1,663 | 1,463 | 1,282 | 1,119 | 973 | 845 |
AVERAGE | 1,680 | 1,416 | 1,187 | 988 | 818 | 672 |
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.300 AAC BLK | Muzzle (ft-lbs) | 100 | 200 | 300 | 400 | 500 |
110-grain Varmaggeddon(Nosler) | 1,182 | 909 | 690 | 521 | 396 | 312 |
120-grain Power-Shok(Federal) | 1,175 | 863 | 626 | 455 | 344 | 279 |
120-grain VOR-TX(Barnes) | 1,175 | 949 | 760 | 605 | 484 | N/A |
125-grainPremier Match(Remington) | 1,362 | 1,084 | 854 | 669 | 523 | 415 |
150-grainPower-Shok JSP(Federal) | 1,202 | 946 | 739 | 580 | 465 | 388 |
AVERAGE | 1,219 | 950 | 734 | 566 | 442 | 349 |
The .300 AAC Blackout packs heavier rounds, which tend to deliver higher energies. Despite the weight advantage, the speeds of the 6.5 Grendel transition into higher muzzle and downrange energies.
At 300 yards, most 6.5 Grendel loads have around 1,000 ft-lbs of energy, a benchmark for hunting ammo. The Blackout mostly drops below 1,000 ft-lbs by 100 yards; by 300 it’s averaging 566 ft-lbs; none of the rounds we examined had over 700.
Trajectory
6.5 Grendel | 100 | 300 | 400 | 500 |
90-grain Varmageddon(Nosler) | 0 | -9 | -25 | -51 |
100-grainELD-VT V-Match(Hornady) | 0 | -8 | -24 | -49 |
115-grain TAC-TX BT(Barnes) | 0 | -10 | -29 | -59 |
120-grainFusion MSR(Federal) | 0 | -10 | -31 | -63 |
130-grain Premier Match(Remington) | 0 | -10 | -30 | -60 |
AVERAGE | 0 | -9 | -28 | -56 |
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.300 AAC BLK | 100 (inches) | 300 | 400 | 500 |
110-grain Varmaggeddon(Nosler) | 0 | -16 | -49 | -103 |
120-grain Power-Shok(Federal) | 0 | -20 | -60 | -127 |
120-grain VOR-TX(Barnes) | N/A | N/A | N/A | N/A |
125-grainPremier Match(Remington) | 0 | -15 | -45 | -93 |
150-grainPower-Shok JSP(Federal) | 0 | -21 | -62 | -129 |
AVERAGE | 0 | -18 | -54 | -113 |
We are starting to see a trend. When it comes to downrange performance (which, to be fair, was never the intention of the Blackout), the 6.5 Grendel is the top performer.
While shooters can adjust, a drop of ten feet is nearly impossible for most shooters to handle. At 500 yards, the .300 Black simply can’t maintain the same performance.
From Grendel to Blackout; We Have the Ammo You Need
If you are looking for the most affordable prices on high-quality ammunition, visit our site today. You’ll find affordable prices for top-quality cartridges from the biggest names in ammo, including Remington, Federal, Fiocchi, Prvi Partizan, Winchester, and Barnes.