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6.5 Grendel vs .300 Blackout

Ballistics Performance Comparison of 6.5 Grendel vs .300 Blackout

The 6.5 Grendel and the .300 Blackout are both intermediate cartridges intended for hunting, and primarily used on the AR-15 platform. However, there are key differences between them that can make each caliber better for various purposes. The 6.5 Grendel is a good round for large and medium game, while the .300 Blackout is a medium and small game cartridge. By comparing side by side, you can determine which caliber is best for your unique needs.

6.5 Grendel vs 300 Blackout

The following ballistics tables show a side by side comparison of the 6.5 Grendel vs .300 Blackout based on bullet weight and various performance metrics including velocity, energy, usage and recoil.

6.5 Grendel 123 gr vs .300 Blackout 125 gr Cartridge Comparison Table.

6.5 Grendel 300 Blackout
Bullet Velocity (Muzzle) 2,580 ft/s 2,175 ft/s
Bullet Velocity @ 100 yds 2,410 ft/s 1,932 ft/s
Bullet Velocity @ 200 yds 2,246 ft/s 1,708 ft/s
Bullet Velocity @ 300 yds 2,088 ft/s 1,505 ft/s
Bullet Energy (Muzzle) 1,818 ft⋅lb 1,313 ft⋅lb
Bullet Energy @ 100 yds 1,585 ft⋅lb 1,036 ft⋅lb
Bullet Energy @ 200 yds 1,377 ft⋅lb 810 ft⋅lb
Bullet Energy @ 300 yds 1,191 ft⋅lb 609 ft⋅lb
Usage @ 0 yds Large Game Medium Game
Usage @ 100 yds Large Game Medium Game
Usage @ 200 yds Medium Game Small Game
Usage @ 300 yds Medium Game Small Game
Recoil Energy 7.9 ft-lbs 3.32 ft-lbs
Recoil Velocity 8 fps 4.95 fps
Recoil Score* 2.05 1.47
*Cartridge ballistics, usage and recoil figures takend from Sportsman's Warehouse rifle ballistics and rifle recoil tables. Recoil score based on weighted average of recoil energy and recoil velocity normalized between 1 and 10.


The 6.5 Grendel flies faster than the .300 Blackout, even at bullets of similar weights. We can see from the above chart that the 6.5 Grendel is moving 405 ft/s faster at the muzzle than the .300 Blackout is. As we get out to 300 yards, that difference has already increased to the 6.5 Grendel being 583 ft/s faster than the .300 Blackout. It’s important to remember that this is the difference when the bullets are comparable weights: if you use the heavier bullets offered by the .300 Blackout, this will slow the velocity more.


The 6.5 Grendel has a significant advantage over the .300 Blackout when it comes to ballistics when we analyze bullets of similar weights. As seen in the above chart, the 6.5 Grendel starts with an advantage of 505 ft-lbs right out of the muzzle, and this discrepancy stays fairly consistent right out to the 300-yard mark, where the 6.5 Grendel is ahead by 582 ft-lbs.

However, it is important to remember that the .300 Blackout can provide a much heavier bullet than the 6.5 Grendel. While this means more drop over long distances (where we’ll see the .300 Blackout is already at a disadvantage), it does mean more energy at shorter distances. If you’ll be hunting in close ranges and want heavier bullets, the .300 Blackout may be a strong choice.


Thanks to its higher ballistics, the 6.5 Grendel has a flatter trajectory than the .300 Blackout. This is especially true at longer distances, and rifles chambered in the 6.5 Grendel will also shoot much farther than .300 Blackout rifles. The .300 Blackout usually drops at about 300 yards or so, while the 6.5 Grendel will not drop until past the 600-yard mark. This flatter trajectory can help you hit your target more accurately, which is crucial to ensure a clean, ethical kill.

The superior trajectory of the 6.5 Grendel also makes it a better choice for long distance shooting. It can still do well up to 300 yards in shorter barrels, and you can find strong hunting rifles chambered in 6.5 Grendel with 12” barrels. The .300 Blackout’s effective range is 400 yards, while the 6.5 Grendel’s is past 800 yards.

Rifle Type

The 6.5 Grendel was specifically developed as a big game hunting cartridge on the ever-popular AR-15 platform. The .300 Blackout can also be used on the AR-15 platform, as long as you don’t mind customizing your firearm and swapping out the barrel. It is considered the only semi-automatic cartridge that can easily feed both super and subsonic. The 6.5 Grendel is known to wear out barrels a little more easily, but this may not be an issue if you are primarily using your rifle for hunting and won’t be firing too many rounds through it.


The 6.5 Grendel is a highly versatile cartridge that has gained popularity in recent years. It is therefore available in a wider variety of factory rounds. Many shooters prefer to test ammunition from different manufacturers to discover which works best with their firearm and shooting style. It is also less expensive than the .300 Blackout, which can be important especially if you are shooting a large number of rounds through target practice or some other activity.


The 6.5 Grendel and the .300 Blackout have the same exact length, at 2.26”. the diameter of the .300 Blackout is just a bit larger, at 0.308” compared to the Grendel’s 0.264”. Both calibers have a variety of bullet weights on the market, but the 6.5 Grendel generally has lighter bullets than the .300 Blackout can offer. The 6.5 Grendel can be shot with bullets ranging from 90-130 grains, while the Blackout offers bullets from 78-225 grains.

Which Caliber is Best?

The 6.5 Grendel is certainly the more powerful cartridge compared to the .300 Blackout, even though it has a lighter bullet. However, it also has a significantly more powerful recoil than the .300 Blackout. If you’ll be shooting small and medium game at distances less than 300 yards, the .300 Blackout may be all you require. If you are targeting larger game at longer distances and can handle the additional recoil, the 6.5 Grendel will give you more options.

Disclaimer: Sportsman's Warehouse assumes no responsibility or liability for any errors or omissions of the information on this page. Although we strive to provide the most accurate information as we can the information contained in this page is provided on an "as is" basis with no guarantees of completeness, accuracy, usefulness or timeliness.