6.5 Grendel vs 300 Blackout – Ammo Comparison

Both these cartridges have been introduced relatively recently. They were created to solve the same problem – providing a better performing cartridge than the 5.56mm NATO. The 6.5 Grendel is a mid-power 26 caliber, and the 300 Blackout is a low-power 30 caliber cartridge, both compatible with the AR-15 platform. However, how do they compare, and in which category does each cartridge excel? Let’s find out.

What Is The 6.5 Grendel?

Introduced to the public in 2003, the 6.5 Grendel is an intermediate mid-power 26-caliber cartridge designed by Alexander Arms. It is a low-recoil, highly accurate rifle cartridge specifically used in the AR-15 platform for medium to long-range shooting (200 to 800 yards).

Just like we saw with our comparison of the 6.5 grendel vs 350 legend, the 6.5 Grendel was designed to replace the 5.56mm NATO or .223 Remington cartridge. Using the .220 Russian as a parent case, the case of the 6.5 Grendel was modified to have a characteristic shorter but larger diameter case to allow high powder volume. Yet, still allow enough space for the long, high ballistic coefficient 6.5mm bullets.

• Bullet Size: 2.26 inches
• Bullet Diameter: 0.308 inches
• Shell Case Length: 1.368 inches
• Case Capacity: 19.2 gr
• Max Pressure (SAAMI): 55,000 psi

What Is The 300 Blackout?

The 300 Blackout was designed by Advanced Armament Corporation (AAC) as a lower-power 30-caliber cartridge. The cartridge is widely used in rifles with a shorter barrel as it yields increased performance compared to the 5.56mm NATO.

The 300 Blackout was designed for use in the M14 carbine and AR-15 rifles to perform best at close range with suppressed and short barrels. The parent case of the 300 Blackout is the .223 Remington. Be sure to read about the different parts of a bullet to learn more about this.

• Bullet Size: 2.26 inches
• Bullet Diameter: 0.264 inches
• Shell Case Length: 1.52 inches
• Case Capacity: 35 gr
• Max Pressure (SAAMI): 52,000 psi

Main Differences Between 6.5 Grendel vs 300 Blackout

Ballistic Performance: 300 Blackout vs 6.5 Grendel

Velocity

Using a 123-grain bullet, the 6.5 has a high velocity. If you want to see a more high powered round, check out the 44 40 ballistics as well.

• Muzzle velocity – 2,580 feet per second 
• 100 Yards – 2,375 fps
• 200 Yards – 2,179 fps
• 400 Yards – 1,816 fps

Meanwhile, using a 125-grain bullet, the 300 Blackout has a velocity of:

• Muzzle velocity – 2,175 feet per second
• 100 Yards – 1867 fps
• 200 Yards – 1,591 fps
• 400 Yards – 1,168 fps

It is evident that the 6.5 Grendel has a higher muzzle velocity, 400 fps to be precise. The 6.5 Grendel also retains more velocity long range, losing only 700 fps at 400 yards, compared to the 300 Blackout, which loses 1000 fps at 400 yards. Also check out the comparison of 350 legend vs 357 magnum ballistics if you want to explore other rounds.

Muzzle Energy

Just like we saw when comparing the 17 vs 22, muzzle energy plays a significant role in stopping power.

Again using a 123-grain bullet for the 6.5 Grendel, it has an energy of:

• Muzzle energy – 1,818 feet per pound
• 100 Yards – 1,540 ft./lbs
• 200 Yards – 1,297 ft./lbs
• 400 Yards – 901 ft./lbs

The 300 Blackout, using a 125-grain bullet, has an energy of:

• Muzzle energy – 1,313 feet per pound
• 100 Yards – 968 ft./lbs
• 200 Yards – 703 ft./lbs
• 400 Yards – 379 ft/lbs

The 6.5 Grendel beats the 300 Blackout in kinetic energy, providing 500 ft./lbs more energy from the muzzle. It also possesses significantly more energy downrange, 500 ft./lbs. Just like we saw in our comparison of the 32 winchester special vs 30-30, muzzle energy can be a big difference maker!

Ballistic coefficient

Ballistic coefficient measures how aerodynamic a specific bullet is, a heavier bullet typically has a higher ballistic coefficient. It can retain its kinetic energy for a longer period and experiences less wind drift. This is very similar to what we saw in our comparison of 350 vs 450 Bushmaster ammunition.

With subsonic ammo, the 300 Blackout has a higher ballistic coefficient. However, they will have a shorter effective range because they are so much slower and heavier than the lighter bullets.

On average, the 6.5 Grendel has a better ballistic coefficient enabling it to have a flatter trajectory and better penetration than the 300 Blackout. Also, it likely uses something similar to the 6.5 creedmoor primer that I’ve tested.

Overall the 6.5 Grendel is a better cartridge than the 300 Blackout, ballistics-wise. Many shooters will ask simple questions like, how fast does a 22 bullet travel? The answer will really depend on the rounds ballistic coefficient!

Which Has More Bullet Drop?

For a 123-grain bullet, the 6.5 Grendel has a trajectory as follows:

• 100 Yards – 0 in drop
• 200 Yards – -4.69 in drop
• 3oo Yards – -16.73 in drop
• 400 Yards – -37.56 in drop

The 300 Blackout has a trajectory of:

• 100 Yards – 0 in drop
• 200 Yards – -8.58 in drop
• 3oo Yards – -31.01 in drop
• 400 Yards – -72.52 in drop

The 6.5 Grendel performs better at longer ranges than the 300 Blackout, having less drop and a flatter trajectory. It even has less drop than flatter trajectory than the 300 hammer ammo that many use today!

Cost Comparison: 300 Blk vs 6.5 Grendel

Both these two cartridges’ ammo is less common than some other circulating cartridges. The lower supply means that ammo cost tends to be more expensive. Looking at the cheapest ammo available, you can expect to pay:

• 6.5 Grendel – $1 per round
• 300 Blackout – $0.75 per round

The 6.5 Grendel also has heavier loads than the 300 Blackout, which means hand loading will also be more expensive for the 6.5 Grendel. They are very similar to the 350 Legend or 223 in pricing.

If you are looking for the cheapest of the two rounds, then the 300 Blackout is the cartridge for you.

Stopping Power Comparison: 6.5 vs 300 Blackout

Stopping power determines, in part, how efficiently the given caliber with the given cartridge can take down a target.

Even though the 300 Blackout makes a wider hole than the 6.5 Grendel, the ballistic performance of the 6.5 Grendel is hands down better. The 6.5 Grendel delivers more power with better penetration on the target at any given range, making it better in terms of stopping power. Both rounds are probably stronger than the 17 WSM or 223 Rem ammo.

Recoil Comparison: 6.5 Grendel vs 300 Blk

The 6.5 Grendel has 4.02 lbs of recoil compared to the 300 Blackout, which has 6.89 lbs of recoil. In the recoil category, the 300 Blackout takes the win with almost 40% less recoil than the 6.5 Grendel.

It also has better suppressor performance than the 6.5 Grendel, making it a better cartridge for short-range shooting or learning novice shooters. Also, be sure to research the difference between centerfire vs rimfire rounds to further understand these types of ammo.

Weapon Compatibility

Hunting

Short Range: Within 100 yards, there is a negligent difference in hunting performance. Both these cartridges are excellent for feral hogs, whitetail deer, and other deer-sized game. Thus on closer ranges, they are equally matched.

Long Range: Beyond the 100 and 150-yard mark, the gap widens. The superior terminal ballistics and flat trajectory of the 6.5 Grendel make it the better long-range hunting cartridge. The 6.5 Grendel is excellent up to 300 yards for taking down elk, mule deer, and other larger game.

If you are looking for a close-range varmint hunting cartridge, then the 300 Blackout is the better option, with its increased suppressor performance. However, you will be predominantly limited to game the size of whitetail or smaller and within 150 yards.

However, if you want the versatile option, then the 6.5 Grendel is the way to go with its precision shooting and long-range performance. It can take down larger game and is excellent up to 300 yards.

Self-defense

Having a rifle as a personal defense weapon is never ideal, it is difficult to maneuver and aim at close range. Nonetheless, if there had to be a self-defense winner, it would go to the 300 Blackout.

The 300 Blackout is designed for close-range shooting, and the cartridge is normally shot from guns with short barrels. Making it more maneuverable than the 6.5 Grendel, the lower recoil also counts in favor of the 300 Blackout. If you want to supercharge your weapon, consider buying one of the best 300 Blackout optics to make self defense even easier!

Sport Shooting

Short Range: Again, these two rounds are very similar within 100 yards. However, target shooting within 100 yards, the 300 Blackout takes the crown. Because the 6.5 Grendel has an $0.15 per round extra cost and 40% more recoil.

Long Range: No debate here, the 6.5 Grendel is the better choice for punching paper at ranges exceeding 150 yards.

Which Should You Choose?

If you plan to hunt in forest areas at a range not exceeding 150 yards and predominantly on small to medium game, then the 300 Blackout will work just fine.

But of course price will play a major role. For example, many shooters will ask questions like why is 380 ammo so hard to find? The answer is because it is too expensive!

However, my choice is the 6.5 Grendel, the range and increased power make it a better overall cartridge for hunting and use in the AR platform with its superior ballistics.

Frequently Asked Questions

The Bottom Line

Both these cartridges are excellent. However, after firing numerous shots and hunting with both cartridges, I can safely say the 6.5 Grendel is the better cartridge. The flat trajectory and more energy make it a better option for hunting game or shooting competitively at short and longer ranges.