5.56x45 vs 7.62x39: The Battle Rifle Blitz

When it comes to selecting a semi-automatic rifle cartridge, the 5.56x45mm NATO and the 7.62x39mm are always front and center in the conversation.

Both rifle rounds have been forged in the fires of battle from Vietnam, Iraq, and Afghanistan as well as a host of other conflicts across the globe. As a result, they are two of the most popular rifle cartridges on the planet.

Virtually every military on Earth uses one of these two rifle rounds for their primary battle rifle. And there’s a good reason for that! Their terminal ballistics and effectiveness in close quarters battle (CQB) are second to none.

But which rifle cartridge is better suited for you and does it matter?

Let’s take a closer look at the caliber debate that defined world conflict since the Cold War, the 5.56x45mm NATO vs 7.62x39mm.

A Note on Nomenclature: 223 Remington vs 5.56 NATO

Please note that within this article we will refer to the 223 Remington (223 Rem) and the 5.56x45mm NATO round interchangeably.

There are differences between the two and you can read about them HERE.

In short, a 223 Rem can safely be fired from a rifle or handgun chambered in 5.56, however, the opposite is not true.

5.56 vs 7.62x39: Let the Caliber Cold War Begin

Ever since the Vietnam War when the 5.56 and 7.62x39mm first squared off toe-to-toe, many militaries around the world have adopted one of these rifle cartridges as the chambering for their primary battle rifle. This has led many internet gun forums to delve into intense heated debates over the combat effectiveness and lethality of each round to determine which one is “best”. Most of these caliber debates come down to terminal ballistics, effective range, stopping power (ft-lbs), muzzle velocity (FPS), accuracy, and bullet weight.

In one camp, we have the 7.62x39 comrades with their AK-47 assault rifles, AKM variants, SKS rifles, and RPK machine guns. They tout the 7.62x39 as firing a heavier bullet that hits with the kinetic energy equivalent to Thor’s Hammer, superior barrier penetration, and enough stopping power to put a Siberian brown bear into permanent hibernation.

And in the other camp are the marksman of the 5.56 NATO cartridge with their beloved AR platform, M4 carbine, or bolt action varmint rifles. These shooters proclaim that “speed kills” and a lighter-weight bullet traveling at high muzzle velocity and higher pressure are preferred as they cause massive amounts of damage via hydrostatic shock. With a flatter trajectory and less recoil, the 5.56 shooters proudly boast of their sniper rifle accuracy over longer ranges than the slow and chunky 7.62x39 crowd could only dream of.

I hope you enjoyed some sarcasm there, but sadly this is what the caliber debate has come to in some forums.

The truth is that both rifle rounds are extremely effective in close-quarters battle and engagements at longer ranges, and this has been proven many times over in Iraq and Afghanistan. No matter which semi-automatic rifle cartridge you choose, it will not fail to deliver in any self-defense situation.

However, which ammo will be best for you is a deeper question that warrants a broader comparison of the 5.56 NATO round and the 7.62x39. Let’s begin by analyzing the Cartridge Specs for each.

Cartridge Specs

When evaluating two rifle rounds, it’s a good practice to look at the cartridge specs to see how they compare. And although the 5.56 and 7.62x39 couldn’t be more different from one another, there are some nuances that we can evaluate from the spec chart.

556 vs 762 dimension chart

The first major difference is the bullet diameter each cartridge fires. The 5.56 fires a 0.224” diameter while the 7.62 fires a 0.312” diameter bullet.

This is one flaw in the Russian nomenclature that confuses some new shooters, as the 7.62x39 does not fire a 7.62mm (0.308”) diameter bullet like the 7.62x51 NATO (308 Winchester). Instead, it fires a 0.312” diameter bullet like the 303 British cartridge.

This lets us know that the 7.62x39 will likely be firing a heavier bullet at a lower muzzle velocity while the 5.56 will be firing a smaller bullet at a higher muzzle velocity (FPS).

The wider base diameter of the 7.62 allows for more case capacity than the 5.56, which is needed to push those heavier caliber bullets at an acceptable velocity to be effective at longer ranges. On the other hand, the 5.56 has a longer overall length as it is a thinner, longer case while the 7.62 is shorter and wider.

The last major difference is the maximum pressure. The 5.56 creates higher pressure in the chamber to reach those higher velocities needed to be combat effective, whereas the 7.62x39 can get by with lower pressures.

One note on the maximum pressures listed, the 5.56 NATO round is not registered with SAAMI, so the pressure limits listed are based on CIP data.

Now that we have a clearer understanding of the cartridge specs, let’s talk about recoil.


Although both rifle rounds are becoming more popular in the hunting community, they are first and foremost frontline ammunition for combat troops. As such, having a round that has less recoil is preferred as it allows for faster follow-up shots during semi-automatic fire.

Both the 5.56 and 7.62 have very low recoil when compared to larger rounds like the 308 Winchester, 30-06 Springfield, and 7.62x54R.

Felt recoil is primarily a function of bullet weight, case capacity, and rifle weight. Therefore, a heavier bullet with a larger powder charge will recoil more than a lighter bullet with a lower powder charge.

A 7.62x39 will typically fire a 123 grain bullet while the 5.56 NATO cartridge will typically fire a 55 or 62 grain bullet (although heavier bullets can also be used).

Assuming a 7-pound rifle, the 7.62 will have approximately 8.5 ft-lbs of felt recoil compared to 5 ft-lbs of felt recoil for the 5.56 NATO round. And this is not overly surprising as the 5.56 is firing a considerably lighter bullet (albeit at higher muzzle velocity) than the 7.62x39.

Now it’s true that the 5.56 has less recoil, and this is preferred, but the recoil from the 7.62 is not oppressive by any stretch of the imagination. Shooters should not experience much of a recoil flinch from either round as they are both very pleasant to shoot.

Recoil is further mitigated in the AR platform due to the use of the buffer tube and recoil buffer to soften the reciprocation of the bolt carrier group (BCG) during firing. Many shooters who utilized the AR-15 describe it as having virtually zero recoil, which makes it a dream to shoot.

One major difference when it comes to recoil is the difference between semi-auto vs full-auto fire (AKA the happy switch). In the case of fully automatic fire, there is a noticeable difference between the two rifle rounds. The heavier recoil of the 7.62 will be more difficult to control during full auto when compared to the 5.56.

I know because I’ve shot both!

Now, for mounted machine guns or those using a bipod, such as the RPK or the M249 SAW, there will be little difference in full auto as the mount or bipod will help mitigate muzzle rise.

However, when it comes to muzzle rise while using an assault rifle, the M4 carbine and 5.56 NATO cartridge are easier to control.

The short-stroke gas piston, lack of a recoil buffer, and overall heavier recoiling round for the AK-47 lends itself to more muzzle rise during automatic fire. Although it’s not impossible to control the 7.62x39 in full auto, it takes more practice, training, and strength to keep the muzzle down compared to the M4 carbine and 5.56.


Trajectory is how we quantify a bullet’s flight path to its target measured in inches of bullet drop. A flatter trajectory is preferred as it requires less sight adjustment and provides a longer effective range.

Muzzle velocity can affect trajectory as well since a bullet that is moving at high velocity arrive at its target quicker and provide gravity less time to affect its flight path. And when it comes to muzzle velocity and trajectory, the 223 Rem leaves the 7.62x39 eating its dust.

Looking at the ballistics tables below, you can see how much flatter shooting the 5.56 is compared to the 7.62.

At 400 yards, you can see that the 62-grain bullet of the 5.56 NATO round has dropped about 23” while the 7.62x39 has plummeted over 44”. That’s virtually a 2-fold difference between the two rounds.

The 5.56 NATO cartridge was designed to be effective at long-range and short-range engagements, and the lightweight, super high-velocity 55gr and 62gr bullets used by the U.S. military are extremely effective at this.

Although the 7.62x39 can still be effective at range, it requires considerably more sight adjustment to account for the massive bullet drop the round experiences outside of 300 yards.

In terms of trajectory, the 5.56 NATO cartridge is undoubtedly the flatter shooting round.


The 7.62x39 has gotten somewhat of a bad rap as being an inaccurate round. Some of this is likely due to inconsistencies in the ammo itself and the rest is inherent to the AK platform specifically.

Former Communist Bloc manufacturing processes were not exactly ISO 9001 Certified if you catch my drift. Therefore, sometimes inconsistencies in powder charge or bullet seating depth of 7.62x39 ammo have been observed, and these differences between rounds will affect the point of impact. Reliability is always important in a battle rifle and the AK platform is known for its undying reliability. However, to achieve this the AK was designed with looser tolerances (especially in the chamber), and this often leads to decreased accuracy. Furthermore, the majority of 7.62 cartridges are steel cased, which does not allow the case to form to the chamber during firing.

To learn more about Steel Cased Ammo Click HERE.

But what about newly manufactured 7.62 ammo?

Newly produced 7.62x39 ammunition is considerably more consistent than its surplus predecessor from the spam can. However, most of your cheap steel-cased ammo is not going to be match grade, even the more expensive 7.62x39 will not compare with the consistency of 5.56 ammo. With optimized handloads for 7.62x39, I suspect that MOA level accuracy could be obtainable for a solid marksman. However, most off-the-shelf 5.56 cartridges will be more consistent and accurate than 7.62x39.

Ballistic Coefficient

Ballistic Coefficient (BC) is a numerical representation of how well a bullet resists wind and air resistance. It’s a measure of how aerodynamic a bullet is, a high BC is preferred and means the bullet will buck the wind easier. The way a BC is calculated is rather complicated and irrelevant for this article, however, heavier bullets will typically have a higher ballistic coefficient.You would then logically theorize that the 7.62x39 would dominate in terms of BC as it fires a heavier bullet…but this isn’t the case.

Bullet design also plays a role in the BC calculation, and the shorter/chunkier 0.312” diameter bullets used for 7.62 are not the most aerodynamic. As such, the 5.56 slightly edges out the 7.62 in terms of Ballistic Coefficient. On average, 5.56 will have a BC of 0.29 while the 7.62 sits at 0.27. It’s not a huge difference, but the 5.56 will be slightly more resistant to wind drift.

Sectional Density

Sectional Density (SD) is the measure of how well a bullet penetrates a target. This is extremely important when hunting big game, as you need a bullet that can punch through thick hide, bone, and sinew. Sectional density is calculated by comparing the bullet weight and the bullet diameter, the greater the number the more effective it will be at penetrating a target.

The greater the SD the deeper the bullet will penetrate the target. Although the 7.62x39 uses a heavier bullet weight, this does not correlate with an increase in SD as it is traveling at a slower FPS. In contrast, the 5.56 is moving at a higher FPS and concentrates all its force into a small area.

As such, the Sectional Density comparisons between 5.56 vs 7.62 are virtually identical.


Although both rifle rounds were made for battle, they have both become popular as a hunting round as well. The 223 Remington/5.56 NATO has always been considered a varmint round and is extremely effective on small game like groundhogs, prairie dogs, coyotes, and foxes.

Although the 5.56 is an extremely effective round on two-legged varmints, it is typically not considered a proper round for whitetail. Many states and provinces in North America have a minimum bullet diameter allowed for deer hunting, and typically that bullet diameter is a minimum of 0.243” or higher. This keeps the 5.56 relegated to small game and varmint hunting only.

However, the 7.62x39 can step in as a hunting round that is appropriate for deer, feral hogs, and other medium-sized game. The 1500 ft-lbs of muzzle energy generated by the heavier 123-grain 7.62 bullet is more than enough to fall a deer out to around 150 yards. Hollow point and soft point ammo are currently available in 7.62x39 and provide appropriate terminal ballistics to humanely claim game.

However, many regions have regulations concerning hunting with semi-automatic rifles. Furthermore, the accuracy issues with some AK variants might also make it a less than ideal choice when picking a rifle to take into the woods. That is, of course, unless you want to pretend you are hunting the Viet-Hogs in the brush of the Mekong Delta…if that’s the case then strap up your SKS and go harvest that boar!

However, if you want to milk all the performance possible out of the 7.62 round, a bolt action rifle would be the best choice. In this case, the Ruger American Hunter or the CZ 527 are your primary rifle options.

To summarize, the 5.56 makes an excellent hunting round for varmints and small game with its lightweight bullets, long-range capability, and flatter trajectory. The 7.62x39 is an excellent choice for deer and medium-sized game under 150 yards provided you are using a proper hollow point or soft point bullet for added expansion.

Self Defense/Home Defense

When it comes to self-defense, there’s no denying that both rifle rounds will get the job done. This has been proven on the battlefield for well over 60 years and counting. The 7.62x39 is renowned for its stopping power as it delivers a punishing amount of kinetic energy into its target. In a short-range or CQB context, it’s hard to debate the terminal ballistics offered by the 7.62 are nothing short of spectacular. Therefore many ranchers and farmers will carry a 7.62 rifle like the Ruger Mini-30 or SKS in their truck to dispatch predators or defend their property.

In contrast, the 5.56 offers lower recoil, higher muzzle velocity, and a flatter trajectory at the cost of less muzzle energy. However, as most self-defense conflicts occur under 100 yards, this gives the advantage to the 7.62x39.

But let’s be honest about one thing, it’s unlikely that most of us will be packing our semi-automatic rifle in a self-defense situation unless you live in the country. Since the vast majority of CCW permit holders will be carrying a handgun when they are out in public, the question of home defense becomes a more pertinent question to answer for the 5.56 vs 7.62 debate. And one of the most important factors to discuss when talking about home defense is overpenetration. The absolute last thing any shooter wants is for their round to penetrate through the bad guy and into an innocent bystander.

The 7.62x39 gained quite a reputation in Vietnam for its ability to penetrate barriers and brush. For this reason, the 7.62 is not well suited for home defense. Modern home/apartment construction is notoriously flimsy and a 7.62x39 will have no issues blasting through sheetrock, vinyl siding, and into your neighbor’s unit or kitchen. Although the 5.56 offers a little less kinetic energy, it was developed to cavitate, tumble, and fragment when it entered soft tissue. This causes additional damage to the target and limits overpenetration.

Don’t get me wrong, the 5.56 can easily penetrate through drywall and siding like the 7.62, however, the lighter weight bullets fired by the 5.56 are easier to deflect and should over-penetrate less than the 7.62x39.

Ammo and Rifle Price and Availability

Although ammo prices have been trending up ever since the Coronavirus pandemic, 5.56 and 7.62x39 are still very affordable centerfire rifle rounds when compared to larger cartridges like the 308 Winchester.

When it comes to 5.56 ammo, you can purchase brass-cased or steel cased. We touched on steel-cased ammo earlier, but it is generally cheaper as the steel cases are easier to manufacture at a lower cost.

At the time of writing, steel-cased 5.56 55gr FMJ ammo can be had for about $0.55/round while brass-cased is sitting around $0.60/round if you buy in bulk. That’s not as huge a difference as it used to be, thanks to the Biden Russian Ammo Ban instated in August 2021.

Premium 5.56 rifle cartridges sporting ballistic tips, soft point bullets, or match grade hollow point bullets will generally run you about $1/round. For 7.62x39, long gone are the days of cheap spam cans full of Russian, Yugoslavian, or other Eastern European surplus FMJ ammo. At the time of writing, the cheapest steel cased 7.62x39 pierce your walled for about $0.38/round. Brass cased 7.62 ammo is also available, though it is almost 2 times more expensive, starting around $0.70/round.

As far as firearms are concerned, you have a plethora of options for both when it comes to semi-automatic rifles. You can purchase ARs, AKs, and SKSs in all different variations, colors, and configurations.

As far as prices, sadly they are also trending up just like ammunition. AK-47’s used to be extremely inexpensive and easy to come by, but now they command around a $600-$700 price point for most manufacturers.

The same could be said for AR-15’s, as now they typically start around $700 and only go up from there depending on the manufacturer and add-ons you want. For bolt action rifles, the sky is the limit when it comes to 223 Remington/5.56 NATO. Multiple manufacturers offer bolt action rifles in 223 Rem as it is extremely popular with target shooters and varmint hunters. This is not the case with 7.62x39 and the round is only recently gaining popularity in the bolt action crowd. The Ruger American Hunter and CZ 527 are your only options for a bolt action 7.62x39 rifle currently.


Reloading allows shooters to tailor their cartridges to meet their specific needs. You can adjust the muzzle velocity, muzzle energy, overall length, and bullet type to customize the perfect round for your rifle. The other main benefit of reloading is cost savings, as “rolling your own” is typically cheaper than buying factory new ammo. This is not the case when it comes to 7.62x39 though. As 0.312” diameter bullets are not overly plentiful and 7.62 brass cases are hard to come by, it is cheaper to shoot factory new steel-cased 7.62x39 ammo than it is to reload it.

On the other hand, 223 Rem brass is easy to come by and extremely cheap, as are 0.224” diameter bullets. Therefore, reloading for 223 Remington is very cost-effective and can easily lower your cost per round.

One thing to note that is sometimes confusing for those new to reloading, there are no exclusive 5.56 NATO dies on the market. As the case dimensions for 223 Rem and 5.56 NATO are the same, a 5.56 specific reloading die is not needed.

7.62x39 vs 5.56 Ballistics Tables

Our team here at Ammo.com has spent countless hours scouring manufacturer’s websites to compile the most extensive ballistics data for multiple loadings of 7.62 vs 5.56. Below you will find ballistics tables for each, comparing muzzle energy, muzzle velocity, and kinetic energy for multiple bullet weights.

Continue reading 5.56 vs 7.62x39: The Battle Rifle Blitz at Ammo.com for comparative ballistic data!


sad part of this presentation is it is more a apple versus pear comparison
it should actually have been 5.56 vrs 5.45.or historically closer to 8mm kurz vrs 7.62 x 39


.300 BO and 7.62x39 is an interesting comparison.

5.45x39mm seems superior to most milspec 5.56 though.


IMO the the terminal balistics of both cartridges are bettered by the 6.8 SPC REM II. I would say that has been established and is easily verified. Let’s use a 20" inch barrel for fair comparative purposes.

A 7.62x39mm bullet a 123 grain fired at 2,400fps at 400 yards will have just over 500-550fpe.

The M193 5.56x45 bullet a 55 grain fired at 3,260fps at 400 yards will have just over 400fpe.

The M855 5.56x45 bullet a 69 grain fired at 3,000fps at 400 yards will have just over 550fpe

The average 6.8x45 SPC REM II 115 grain fired at 2,650fps at 400 yards will have 750fpe.

Edit: Not to say they aren’t any good or useless. We even have some 5.56 and a son has a 7.62x39 he is very emotionally attached to.


We’ll certainly get to that in the future!


Have to agree for the most part. If you want something that will just knock the shit out of what you hit, use a 308 with the Underwood Controlled Chaos rounds. BWAHAHAHHAHAAA
With that said…
In the house I just use a pistol to get to my shotgun. :grin::rofl:
If things escalate, I have a rifle from there…


I run both 7.62x39 and 300 AAC Blackout
Though my blackout is in a suppressed bolt gun only. (No mixing 556 and 300!)
My 7.62s are of various designs… from the Sig 556R (love that rifle) to the IWI Galil ACE and an Arsenal under folder.
I keep mags loaded that are staggered with HP and ball rounds. :grin::stuck_out_tongue_winking_eye:
But in reality, I kinda view both those calibers as the same (supersonic 300)
Only reason I like and have a subsonic 300 is for VERY close range suppressed.


Yep, I think @BrianK would agree that is the BO’s sweet spot.



I have some work to do with subsonic though. I haven’t spent much time with it. Right now my HD round is a Maker 85 @ 2300fps for 1k ft/lbs. I figure no over penetration and maybe 6" of penetration. That’s enough.

It’s definitely not a long range cartridge, maybe 200 yards max’ with the right ammo, but what it does it does well. Some might be able to stretch it out to 300 yards. Mine certainly isn’t set up for distance.


I like 5.56 but milspec ammo sucks. Get some 77 gr blackhills ,it’s much much better. I know a guy who hunts boar with it.

5.56 is bare minimum for me though ,it’s the 9mm route for rifle calibers.

I like 6.5 Grendel more than 6.8 SPC though by a wide margin. Not necessarily just for ballistics but for ballistics and shootability.


Re 5.56 you’re right.

If 6.5 Grendel works for you? Cool beans.

But the ballistics superiority thing isn’t really in a apple for apple match up. Yes some of the 6.5G’s BC are better, but the bolt and case of 6.8 SPC is better and the SPC ll ARP Chamber is not only able to be loaded longer and to 62K PSI it doesn’t have feeding issues.

“Using factory ammo the 6.8 is apx 100fp faster than the Grendel using the same weight bullet and same length barrel. Out to 175 yards the 6.8 has more energy with 110 and 120gr loads. A 16” 6.8 loaded with factory Hornady 120gr SSTs has enough velocity to expand and energy to take deer and hogs at 400yds. The Grendel horde likes to say the 6.8 is a short range hunting round and the Grendel is long range…BS. Load a 130gr Berger Classic Hunter (BC .497), 130 Speer or Sierra BT in the 6.8 and it will push it to the same velocity as a 123gr 6.5 Grendel. The BCs are very close so the drop and drift will be very close way past ethical hunting distances and the 6.8 bullets actually expand as designed.

There are defensive bullets like the 90gr Gold Dot, and several fmjs. There are bonded hunting bullets like the 100 and 110 Accubond, premium solid copper bullets Barnes 85 TSX, 95TTSX, 110 TSX, Cavity Back 100 and 120 MKZ and Hornady 100 GMX.
The 6.8 mags feed better, metal and Magpul SIX8 mags. The bolts and extractors are stronger and more durable than Grendel based cartridges." - Harrison Bean Designer of the 6.8 ARP Chamber.

Energy for the SSA 140 is over 500 foot pounds at 800 yards. Still supersonic at 1,000 yards.


Fair points. I don’t much care for either enough to invest in them anymore to be honest but I enjoyed shooting 6.5g ARs more than the one 6.8 SPC chambered one I tried out.

5.56, .308, and 6.5 Creedmoor are more my thing. 5.56 with good ammo being my home defense choice.


There are 5 ubiquitous firearms Americans should own. Firearms so common that ammo availability will not be the reason they lose value. They will still hold their value vs more esoteric firearms when the mail ceases to run.

22LR Rifle, 12 ga Pump Shotgun, 9mm Pistol, 5.56 AR type and .308 Rifle. These five can nearly do it all. Pretty much dealing with most tasks firearms are called on to do.

After that its fine tuning for special purposes or wants. The Great Bears, ELR, Anti Material, CQB, Home Defense, Scout, or even what I call inside the wire weapons. This is where the 6.5 G and 6.8 come in I guess, Special purpose…

Some folks in our part of the world felt the 6.5 G filled a need or want they had. I was almost there too. The 5.56 with the correct bullet is a formidable low recoil weapon, and it has to much going for it to just walk away from it, but lethality at distance isn’t its strength.

Fortunately for me somebody educated me on the truth of SPC II and then I discovered the ARP chamber and 3R rifling with 1:11 Twist and 110 ABs pushed to 2800fps. I am not sure there is a better AR based all around hunting cartridge.

I will never get rid of my ARs in 5.56 or 6.8s love em both. But if I build a super light walking BA rifle it will be in 6.8 SPC, not 5.56.

BTW 308 Win and 6.5 Creedmoor are 2 more I won’t be letting go either.


They both have an advantage. Who changes their argument from here (5.56 vs 7.62) to 9 vs 45? Meaning changing the standards. With this forum, my guess is very few. But some might.

I don’t agree it is apples vs pears. It is what the west uses for it’s soldiers and the other is for the east. We are comparing what they brought to the table.


Buy them all is the right answer but not all of us are retired drug lords like @Belt-Fed


With the weight of my AR10 and 308 ammo I’ve been contemplating changing to a 15 and .223 :man_shrugging:


Precisely why I never wanted an AR-10.


The pros and cons are more clear than the 9mm vs .45 acp debate, you either want a heavier rifle with much better ballistics, barrier penetration, and range or you want a rifle that is significantly more lightweight with higher capacity.


I just like the big boom from the 308 :grin: :grin: :grin:


Or the big boom from a .30/06 out of a Garand. There’s something about the old rifle that I like a lot.