6.5 Grendel vs 223/5.56: Ballistics, Hunting & Combat

6.5 Grendel vs 223 5.56The 6.5 Grendel vs 223 / 5.56 debate – for  ballistics, hunting or combat – is a LOT like a type of question I get at my day job.  (I do gunsmithing and sales at a local gunstore)

I get asked all the time “which is better?”: 9mm vs 40 vs 45 ACP, 12 gauge vs. 20 gauge, pistol, shotgun or rifle for home defense, etc.  The list goes on and on.

Whenever I’m asked those kinds of questions, I always reply with another question:

“What’s your purpose?”

This debate is no different.

Do you want to plink at the range? Hunt? Go into combat?  If it’s combat, then combat at what range?  Short?  Long?  Medium?  All of the above?  Are you preparing for when the “S” hits the fan?  Do you want one “do everything” cartridge.

What’s your purpose?

Remember that Form Follows function.

If you just want cheap accurate ammo to plink at the range, forget any exotic cartridges (including the 6.5 Grendel) and just get yourself an accurate 223/5.56 rifle.  PMC Bronze 55gr is well reviewed, accurate, consistent, and cheap.

FYI: If you buy after clicking most of the product links on this page, I'll make a few pennies out of each dollar you spend.  It's not much, but it keeps the website going and I would appreciate your support. 🙂

You’ll spend a lot less money throwing lead downrange with a 223/5.56 than the 6.5 Grendel even if you reload.

I will add the caveat that if you are looking to shoot longer ranges, the higher Ballistic coefficient bullets of the Grendel will make shooting in the wind easier.  But at 100 yards (or even 300 yards) in a light to moderate wind the 5.56 will be fine.

Maybe you want more than fine though.

Maybe you want extraordinary.

I’m the same way.

6.5 Grendel vs 223/556 Ballistics

Except for bullet drop, the 6.5 Grendel is ballistically superior to the .223/5.56 in every way.


Sectional Density.

Sectional Density is how “long and thin” versus “short and fat” a bullet is.

Obviously, longer and thinner bullets are more aerodynamic than short fat ones.  Therefore, high sectional Density bullets have a higher Ballistic Coefficient (BC) than low sectional density bullets.

(Ballistic Coefficient (BC) is simply a measure of how aerodynamic a bullet is, with higher being better)

Some of the best 223/5.56 bullets have a BC around .400.  However, 6.5 Grendel bullets are easily found in the .510 BC range, with many bullets being even better.

Because of the higher BC (i.e. more aerodynamic) 6.5mm bullets, the Grendel will drift less in the wind, lose velocity more slowly, and generally be easier to shoot accurately at long range and in the wind.

6.5mm bullets are famous for flying straight and penetrating deeply.

The 6.5 Grendel is no different.

6.5 Grendel vs 223/556 Terminal Performance

The 223 has a reputation for being both worthless and awesome in a fight.  I wrote a whole article on Why 5.56 / .223 is BOTH the Best and Worst AR-15 Cartridge.  It basically boils down to ammunition selection.

Pick good ammo, and the 223/556 is great.

Pick bad ammo, and the 223/556 sucks.

That same could be said of 6.5 Grendel or any other cartridge.

Shocking right?

For hunting or combat, the M855 “green tip” and FMJ ammo are both firmly in the sucks category (unless it’s constructed like the 7n6 bullet of the 5.45×39)

Many people ask me about “Knock Down Power” or “Stopping Power”  in the gun shop.  It makes me laugh (internally) because those terms have ZERO meaning.

No, seriously.

Can you measure “Stopping Power” or “Knock Down Power”?

How many more “Stopping Powers” or “Knock Down Powers” does a .308 have than a 5.56?

Terminal performance isn’t related to kinetic energy either.

Don’t believe me?

Then answer this:

The average football linebacker weighs 230 lbs and sprints at 25.5 FPS. That’s 2020 ft-lbs of energy. A 190gr bullet moving at 2200FPS produces almost identical energy.

Which is more likely to kill an Elk?

Not convinced?

A 490 grain Broad-head arrow traveling at 225 Feet Per Second (FPS) has a kinetic energy of 55 ft-lbs. A 1 Pound Gel filled bag launched at 60 FPS has a Kinetic Energy of 55 ft-lbs.

Same kinetic energy.  One can kill deer deer, but the other would have trouble killing a squirrel.

Energy doesn’t matter.

I wrote a whole article on “Stopping Power” and The Simple Truth of Terminal Ballistics to explain how bullets actually do their damage.

Basically, the bullet must penetrate deep enough to reach the vital organs, and cause cavitation when it passes through them.  A quality hollow point bullet will do that perfectly.


6.5 Grendel vs 223/556 for Hunting

On smaller game it doesn’t matter.

No coyote in the world will know the difference between a 6.5 Grendel vs 223/556 hitting the boiler room (heart/lung area of the chest cavity)

But if you are talking deer sized game or larger, then a 223/556 is a little small.  It absolutely can work, and there are people who hunt deer with a 223/556.  The 223/556 CAN kill a deer.

But I would never hunt deer with a 223/556 for ethical reasons. 

The bullet is too small/light (read: low sectional density) to ensure deep enough penetration and enough cavitation to quickly kill a deer.  The deer might die right there, but it could also run a long way and dying a slow agonizing death.

You CAN do it, but that doesn’t mean you SHOULD do it.

I wouldn’t.

On the other hand, I think the 6.5 Grendel is the ideal size for deer sized game.  (and good for larger game too.)

The 6.5mm bullets have excellent sectional density which translates to excellent penetration.  Plus they have enough weight (momentum) to cause cavitation deep into the wound track.   Exactly what you need for hunting, with the bonus of low recoil which really helps shot placement.

And NOTHING trumps shot placement.

You can’t miss fast enough to win a gunfight or fill a hunting tag. 


I wouldn’t think about hunting deer until you can hit a 9″ paper plate Every Time at 100 yards from a standing position.  That means you’ll hit the vitals at the average range a deer is taken. (40-50 yards)

If we’re talking 6.5 Grendel vs 223/5.56 on bigger game, then forget about the 223/5.56.  I’m not saying it can’t be done.  It can.  But the margin of error is even less.

On the other hand, game up to Elk is within reach if you choose great ammo for for the 6.5 Grendel…


(and this is a big but)

You had better be a GREAT shot before you go after larger game.  I don’t just mean with a 6.5 Grendel either.  I mean with whatever rifle you’re using.  Practice until you can hit everything you aim at with boring consistency.

*imitates Yoda’s voice*  Then, and only then, a Jedi will you be.

Thanks to the high sectional densities of the 6.5mm Bullets, you can take game that is quite large with the “lowly” 6.5 Grendel. Part of that is thanks to modern bullet technology…

…But you have to put those bullets in the right spot.

I don’t care if you’re using a 6.5 Grendel, 223/556, 308 Winchester, 338 Win Mag, or a fire-breathing .500 Shock & Awe Magnum.

You can’t miss fast enough to win a gunfight or fill a hunting tag. 


Firepower is no substitute for accuracy and it never will be.

Don’t pretend it is.

The 6.5 Grendel is a very capable little cartridge, but it has it’s limits.  Yes the Grendel can take Elk at 400 yards as Mark Larue proved.  But Mr. Larue is a good hunter and a great shot.

Most of us aren’t.

For Deer, the 6.5 Grendel is about perfect, and in normal hunting ranges, (40-50 yards) makes an excellent deerslayer.  The 223/5.56, is a little too light in my book.  It can be done, but I wouldn’t try it.

6.5 Grendel vs 223/556 for Combat

I LOVE the idea of a General Purpose Combat Cartridge.  A single cartridge which is effective over the entire range of distances a soldier could engage an enemy is the ultimate in versatility.

And I LOVE versatile equipment.

But the biggest downside of versatile equipment is it loses to specialized equipment when you’re in the specialized equipment’s field.

The 5.56 was designed for Close Quarters Battles(CQB).  From the ground up, it was designed to be highly lethal at close range.  It’s low recoil and high lethality (with good ammo) make the 223/5.56 almost perfect as a close range combat round…


223/5.56 has one glaring flaw: Barrier penetration.

With good ammo, it’s MUCH less of a problem.  However, the relatively lightweight 223/5.56 bullets have very low sectional densities which result in relatively poor performance when faced with barriers.

Unfortunately, barriers are a fact of combat.

Enemy soldiers take cover.  It happens.

When they do, you have two options: either shoot through the cover or wait for them to come out from behind the cover.

(or call in an air/artillery strike.  That works too.)

With good ammo, I would be very happy with 223/5.56 in close quarters, and even out to ~200 yards

However, one problem that’s not solved by better ammo is deflection when shoot through glass.

In Iraq and Afghanistan, one tactic the bad guys used was driving cars or trucks with explosives into US checkpoints.  The easy way to stop the truck is shoot the driver, but the 5.56 bullets tended to travel in odd directions after penetrating the glass.  Often, it takes many repeated shots to hit the driver shooting through the windshield.

Heavier bullets have this problem much less.

By contrast, the 6.5 Grendel was designed from the ground up as a hunting cartridge that would extend the effective range of an AR-15. 

If you’ve read my General Purpose Combat Cartridge article, You’ll know that the 6.5 Grendel only falls a little short of being an ideal one-size-fits-all military cartridge. (partially based on based on military testing, see the article for details)

But the 6.5 Grendel does fall short.

The bullet weight/diameter is right, but the velocity is just too low.

However, it does have a much longer effective range than any other AR-15 cartridge.  (yes, slightly longer than the 6.8 SPC, details in my 6.5 Grendel vs 6.8 SPC article.)

The Grendel has double the recoil and slightly less capacity than the 223/5.56.  The 223/5.56 has issues at longer ranges and through barriers.

If I knew I would only be shooting at relatively close range (0-200 yards) and I knew barrier penetration wouldn’t be an issue, I’d take a 223/5.56 over the Grendel in a heartbeat.

But I can’t know that.

In fact, the opposite is likely to be true. 

Enemy soldiers take cover, windshields are a fact of life, and half the engagements in Afghanistan took place at over 300 yards.

As far as 6.5 Grendel vs 223/5.56 goes, I prefer a more versatile cartridge than can handle varied threats.  The 6.5 Grendel isn’t an ideal General Purpose Combat Cartridge, but it’s better than the 223/5.56.

It has a longer effective range, can punch through barriers better (thanks to it’s higher sectional density and momentum) has a higher hit probability at long range thanks it’s better wind resistance, and a longer effective range thanks to heavier, more aerodynamic bullets.

Conclusion & Misc

The 6.5 Grendel is an Excellent Jack of all trades cartridge….

But it’s not perfect.

223/5.56 is cheaper to shoot, the cheap ammo is more accurate, and has half the recoil. 6.5 Grendel is better at target shooting, hunting, and combat, though more expensive to shoot.

The cheap 6.5 Grendel ammo is the Wolf 100gr steel case.  The price is amazing at only $0.28/round. ($5.60 for a 20 round box. 223 steel case ammo is slightly less at ~$0.24/round or $4.80 for a 20 round box)

Plus, the cheap Wolf 100gr is constructed like the deadly 7N6 bullet used by the Russian military’s 5.45×39.

6.5 Grendel 100 Grain Wolf Steel Case Cutaway

Pinched from a forum post by David Fortier, all credit for the photo goes to him.

See the hollow cavity in the front?  When the bullet hits something that cavity collapses and makes the bullet flip and spin around in all sorts of nasty ways.  It creates a very messy wound track and causes all kinds damage.

It works so well for the Russian 5.45×39, that it’s earned the nickname “poison pill” because it’s so small yet does so much damage.

Yeah, it’s pretty awesome and available for as little as $7/box as I write this in February of 2016.

In virtually every way you compare performance, the 6.5 Grendel vs 223/5.56 is a no contest, no brainer.  However, the 223/5.56 is cheaper to shoot, and the cheap ammo is more accurate (and thus more fun) to shoot at the range.

The 223/5.56 is also arguably better for shooting varmints because the trajectory is flatter over the first few hundred yards.

It doesn’t have to be one or the other.

My solution to the 6.5 Grendel vs 223/5.56 debate is simple: Get both.  AR-15 uppers aren’t hard to swap or too expensive.  You can shoot and practice for cheap with 223/5.56 ammo, and you always have something a little bigger in your stable for  hunting or longer range target shooting.


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