The objective of this comparison is not to label one caliber better than the other. What we will see is that depending on the performance category we are looking at, both of these calibers will excel at some and perform poorer in others. What we want to do is take a look at these ballistic performance categories, compare rounds for each caliber objectively, and in the end, draw conclusions for which caliber is more suited for certain applications.
Every caliber has its niche, and even two calibers that elicit so much debate in the shooting world can reside in the same household. So, let’s first get an idea of where these two calibers come from.
5.56 vs 7.62×39: A Brief History
Before we jump into our comparison, we wanted to briefly touch on where these calibers came from and how they have been used since their introduction. Following that we will cover the design and specs of the cartridges and list several rounds for each caliber that we will be comparing throughout the article.
In the late 1970’s NATO countries agreed that they needed a replacement for the 7.62x51mm round that was currently in use. The issue with the 7.62×51 was that the gun weight, ammunition weight, gun length, and recoil were all not suitable for the type of combat that was currently taking place in the world.
From this, the lighter 5.56x45mm NATO round was brought into existence. It provided a high-velocity round that had a flatter trajectory than its 7.62×51 predecessor. The lighter recoil was more tailored to semi-automatic and automatic firing in the field, and the soldier could carry the same amount or more ammunition at a much lighter weight.
This round was derived from the .223 Remington round, and contrary to popular belief is not exactly the same as the .223. While rifles chambered for 5.56×45 NATO rounds can chamber .223 Rem cartridges, not all .223 chambered rifles can fire 5.56×45 NATO rounds because of the higher pressure generated when firing.
While the 5.56×45 NATO round is known for its military service, it is also extremely popular in civilian circles as the ever popular AR-15 is chambered for these rounds.
Ammunition is widely available and comes in a variety of bullet weights and designs to match the user’s needs. The most common bullet weights range from 50 up 75grains.
The 7.62×39 is one of the most used calibers throughout the world. It was designed in the 1940’s in the Soviet Union to produce an intermediate caliber that could be used in a variety of military settings. In short, an all purpose caliber. From its initial inception, it has undergone numerous design adjustments from then to the modern cartridge we have today.
This cartridge is often highly regarded in close quarters combat as well as in gun shooting competitions. It has recently seen a small increase in popularity in the hunting world as well. One of the most popular rifles in the world is chambered for this caliber, the AK-47 which is an intrinsic part of the shooting world and culture.
The 7.62×39 is available with several different bullets and cartridge designs such as a full metal jacket as well as soft point bullets more suitable for hunting purposes. It is not limited to these bullet designs though and is available in a myriad of designs and jackets. The bullet weight for most 7.62×39 ammunition hangs around the 122-125 grain with some variants in the 150grain range.
5.56 vs 7.62 Specs Comparison
When looking at the specs of these two caliber bullets and their cartridge dimensions, there are a lot of differences that jump out at us. The 7.62×39 uses a bullet with a much wider diameter than the 5.56×45. Yes, while only wider by a tenth of an inch, that is a big difference for bullet design and has a profound affect on ballistic properties.
The 5.56×45 casing and overall cartridge is slightly skinnier and longer than the 7.62×39. While the 7.62×39 round can be packed with more powder than the 5.56×45 NATO, it cannot hold up to the same amounts of pressure as the 5.56 NATO.
To compare these two popular semi-automatic calibers, we have selected four rounds for each caliber that encompasses a wide range of bullet types and weights for an honest evaluation of how these two calibers stack up to each other. Below is a list of the selected rounds.
- 5.56 NATO Hornady BTHP Superformance Match 75gr
- 5.56 Federal American Eagle FMJ 55gr
- 5.56 NATO Winchester FMJ 55gr
- 5.56 NATO Hornady FMJ Black 62gr
- 7.62 Winchester Super-X 123gr
- 7.62 Remington UMC Metal Case 123gr
- 7.62Fusion Soft Point 123gr
- 7.62 Hornady SST Steel Case 123gr
Though these rounds are becoming more prevalent in the hunting world, their main application is still in close to medium range quarters combat situations. These are some of the favorite calibers used in shooting competitions as well, and recoil plays a major role in being able to fire off successive shots accurately.
To compare recoil, we will look at the actual recoil force that is generated when firing a round (ft.lb). While this is not quite the “felt recoil” or the kick as it is often called, it still gives us an idea of what you will have to deal with in the field.
From the first graph, we see that the 7.62×39 caliber has a few more pounds of force generated than the 5.56 NATO. While this is only a small difference in recoil, it might be significant when firing several successive rounds. For single shots, neither of these calibers are going to produce enough kick to cause flinching, at least for experienced shooters,
Let’s take a look at the recoil energy that is generated from our eight selected rounds and see if this trend holds up or if we see a little more variability.
We do see a little variability in the amount of energy generated from round to round within the same caliber grouping, but overall, the trend holds up. You are going to be dealing with a few extra ft.lb of force when firing a 7.62×39 compared to a 5.56 NATO.
We do want to note that these numbers might fluctuate slightly depending on several variables such as gun weight, barrel length, and the amount of powder, especially if being hand loaded.
In this section, we will take a look at several ballistic categories for caliber comparison. Understanding the ballistic properties of each caliber will make it easier to tease apart under which hunting or other shooting applications one round will outperform the other. We will look at velocity, ballistic coefficients, and trajectory at short and long range.
One of the main reasons that velocity is an important category for comparison when comparing two bullets is because it is intricately linked to just about every other ballistic and performance spec we have and will look at. Faster rounds not only get to the target quicker, but they are also less prone to environmental factors that can slow down and through off the trajectory and flight path of the bullet.
Let’s take a look at our eight rounds and see if we can make any conclusions between these two rounds. We will be looking at the velocity (ft/s) from the muzzle out to 500 yards.
When looking at the velocity for the 7.62 vs 5.56, we see a distinct difference between the two calibers. The 5.56, with its much lighter bullet weights and similar powder loads, gives you a much faster bullet from the muzzle out to 500 yards.
While the 7.62 rounds have an overall lower velocity from the muzzle out to 500 yards, they do tend to hold onto their velocity better than the 5.56 where velocity bleeds off rapidly. The rounds from both calibers do maintain supersonic speeds out to 500 yards, except for one of the 7.62 rounds
Ballistic Coefficient (BC)
The ballistic coefficient is a number that is generated from several variables related to bullet design. What this number is going to tell us is how well a bullet is streamlined. The more streamlined, the better the bullet will resist air drag and the less prone it is to wind drift. So, bullets with higher BCs maintain their velocity, force, and trajectory much better than a bullet with a lower BC.
Let’s compare the BCs of our eight rounds and see how these two calibers differ.
Overall, we see very similar ballistic coefficients between these two calibers. All of them hover around the .25-.30 range. The 7.62 rounds seem to be a little closer to the 0.3 mark, but we have also used several full metal jacket 5.56 rounds which are known to drop the BC pretty dramatically.
Again, we should note that the BC is going to differ from round to round. While an average of all of our selected rounds is very similar, like the 5.56 Hornady 75 gr round, there are going to be options for both calibers that have much higher BCs than others.
Before getting into the short and long range trajectory, we wanted to present a graph that gives you a clear picture of how flat the trajectories of these two calibers are.
To do this, we selected a round for each caliber that is made by the same manufacturer and uses the same bullet design. Selecting rounds of similar weight is near impossible with these two calibers as we have discussed before, the 7.62 uses a higher caliber bullet than the 5.56 which often means heavier bullets.
Both of these calibers maintain nearly the same trajectory out to the 180-yard mark. From here, we begin to see the differences between these two calibers. The much lighter 5.56 round can maintain a much flatter trajectory than the 7.62 round and as the yardage increases so does the difference in bullet drop. By the 500 yard mark, the 7.62×39 round has dropped nearly 50 more inches than the 5.56×45 NATO round.
Let’s zoom in and look at sections of these range in more detail.
Short Range Trajectory
For short range trajectory, we are going to compare our selected rounds out to a distance of 300 yards with the test firearms zeroed in at 100 yards. We are measuring bullet drop in inches.
Leading up to the 100-yard mark we do not see any noticeable difference between these two calibers worth mentioning. From the 100 to 200 mark, the gap does widen pretty significantly with around five or more inches difference between the 5.56 and 7.62 rounds. The difference widens even further as the rounds move out to 300 yards. At this point, there is around 10-15″ difference between the two calibers. It is pretty clear that the 5.56×45 NATO rounds show much less bullet drop than the 7.62×39 rounds at short
While this trend will most likely continue at long range trajectories, we will still take a look to see how drastic a difference it is.
Long Range Trajectory
The 7.62×39 caliber has a bad rap when it comes to long range shooting ability, especially when compared to the lighter 5.56×45 rounds. In this section, we will use out eight selected rounds for our 5.56 vs 7.62×39 comparison and see if its reputation is supported by the numbers.
As with the short range trajectory, we are still measuring the bullet drop in inches of our eight rounds. In this section, firearms are zeroed in at 200 yards and data points taken at 100-yard intervals out to the 500-yard mark.
Like the short range trajectory, we again see a significant difference between calibers. Even out to 300 yards there is at least 5-10″ difference in bullet drop favoring the 5.56 NATO. As the range increases so does the difference between the two calibers. Out at 500 yards, there is at most 50″ of difference between the two calibers. The 5.56 NATO rounds lose between 40-50″ while the 7.62×39 rounds drop 90-100″. This is a significant bullet for both rounds, but the 7.62×39 is much more pronounced and will be a major factor in applications for these two calibers.
While stopping power might not be an area of concern for shooters planning on using their firearms on the range, for hunting or self-defense purposes, it is one of the most discussed categories when comparing calibers.
In this section, we will take a look at the energy that is associated with these rounds as they are carried down range. Once the bullets make contact with the target, this energy can cause trauma to the targets tissues and organs. We understand that this energy is not the only factor that is attributed to stopping power. Bullet design also plays a major factor in the type of wound that is created, and penetration of the bullet is also a factor.
We will take a look at penetration as well by looking at the sectional densities of the bullets for our selected rounds, but first, let’s compare the energy of rounds for each caliber.
Out to the first 100 yards, the 7.62×39 rounds have an advantage in stopping power (ft.lb) over the 5.56 NATO rounds. The heavier 75gr 5.56 round performs nearly as well, and we will see that it maintains this force much better than the 7.62 rounds. At 200+ yards, the 7.62×39 rounds begin to bleed off their energy and are very similar to the 5.56 NATO rounds, with rounds of both calibers falling below the 1,000ft.lb mark.
For hunting purposes, this begins to be a concern for bringing down game quickly, but for self-defense purposes, it’s more than enough stopping power. And besides, for home or self-defense in most scenarios, 200+ yard shots are not going to be happening.
Penetration is another factor that goes into a bullet’s stopping power. In this section, we will compare penetration from the two calibers by looking at the sectional densities of the bullets.
The sectional density is derived from a calculation using the bullet’s weight and diameter. The jacketing and design of the bullet is also going to affect a bullets penetration. An example is a full metal jacket. A FMJ expands rapidly which is going to reduce the amount of penetration. For comparison sake, we are going to limit our comparison and discussion to sectional density.
Interestingly, the sectional densities are pretty similar between these two calibers.
While the 7.62×39 might bring a little more energy to the table, its wider diameter means that the penetration drops off slightly. On the other hand, the 5.56×45 uses much lighter bullets, but the small diameter focuses all of the force in a smaller area giving it a sectional density and similar penetration profiles to the 7.62×39 rounds.
Again, there is more that contributes to penetration such as velocity and bullet design, but these numbers can give you a general idea of penetration between the two calibers.
Accuracy is a tough category for trying to compare two calibers. The best method is to take firearms chambered for either caliber, have several different rounds and measure groupings at certain distances. The problem with doing this for an article is that a lot of other variables are in play including environmental and the skill of the one pulling the trigger.
Still, with the categories we have covered so far, we can draw a couple of conclusions when it comes to accuracy when comparing the 5.56 versus 7.62×39.
When looking at the velocities, the 5.56 NATO rounds show a clear advantage over the 7.62x39mm caliber rounds. This increased velocity, as we mentioned briefly will help keep the 5.56 rounds on path. Conversely, the 7.62×39 rounds show an average ballistic coefficient that is slightly higher due to the heavier bullet weights which could argue that these rounds will resist drag and wind drift more efficiently than the 5.56 NATO rounds.
When we look at the trajectory, especially out past 200 yards, the 5.56 is much flatter than the 7.62×39 rounds. While the stopping power is significantly different, we are just sticking with accuracy, and less bullet drop is going to make putting a bullet on target all the easier.
Price and Availability
Luckily for us, ammunition availability and prices for these rounds continue to go up and down respectively. Both calibers are readily available from many retailers that carry ammunition, and these calibers are also available in bulk. We have listed the prices of the eight rounds we have used in our comparisons. We listed a price for 20 rounds, but you can save some money when buying these calibers in bulk.
In today’s market, both calibers are going to be around the same price. The 7.62×39 might be a little more expensive, but it’s not by a whole lot.
As far as options go for specific rounds of both calibers, you will have a much wider selection of 5.56x45mm ammunition than the 7.62×39. This goes for jackets and bullet weights, and bullet designs.
|5.56 NATO Hornady BTHP Superformance Match 75gr||$28.47 (20 Rounds)|
|5.56 Federal American Eagle FMJ 55gr||$7.99 (20 Rounds)|
|5.56 NATO Winchester FMJ 55gr||$8.99 (20 Rounds)|
|5.56 NATO Hornady FMJ Black 62gr||$18.33 (20 Rounds)|
|7.62 Winchester Super-X 123gr||$27.49 (20 Rounds)|
|7.62 Remington UMC Metal Case 123gr||$19.79 (20 Rounds)|
|7.62Fusion Soft Point 123gr||$21.99 (20 Rounds)|
|7.62 Hornady SST Steel Case 123gr||$47.25 (20 Rounds)|
From our experience and research, the 7.62x39mm offers a lot more options when it comes to hunting more medium sized game. This is especially true for bullet designs that are better suited for deep penetration through heavier tissue and bone. The issue is the range of the caliber. For shots within 100 yards, you have a fair shot at good bullet placement, and with the stopping power of the heavier bullets, you should be able to make a clean kill.
The 5.56×45 NATO can also be used in some hunting situations for smaller game up to whitetail deer, but it has pretty limited range because of its loss of energy downrange.
For longer range shooting, the 5.56×45 NATO offers a much flatter trajectory than the 7.62×39. For target shooting, this is a huge advantage as fewer adjustments, which gives you less chance of miscalculation, means a greater chance of landing successive shots on target. For hunting purposes, the long range trajectory does not help the 5.56x45mm only because of its loss of force as it moves downrange. Of course, it also depends on the type of game you are hunting. For some predators and varmints, it still carries enough force to make a clean kill at increased distances.
The 7.62×39 caliber just shows too much bullet drop to be an effective round out past the 300-yard mark. We are sure there are sects who would disagree, and those are also people with years of experience using the caliber. In general, it’s not a great long range caliber.
For ranges out to 200 yards, both of these calibers have flat trajectories and do not need heavy adjustments to shot placement. At shorter ranges, it comes down to other performance specs when trying to select the best caliber for you.
The 5.56×45 has much higher muzzle velocities but bleeds it off pretty quickly. On the other hand, the 7.62×39 carries greater ft.lbs of force. The greater force also means slightly more recoil than the 5.56×45. While only a few ft.lb more, after a long day of shooting, it can become apparent and even affect accuracy. Both of these calibers are readily available and are around the same price ranges. If you’re just going out to the range for some fun, you can bulk of these two calibers for relatively cheap.
Conclusion – 7.62 vs 5.56
When comparing the 5.56 vs 7.62×39, it’s too often we see two sides of the argument unwilling to be swayed or be open to the benefits of the other caliber. Both of these calibers are steeped in history, and both of them offer numerous advantages.
Too often shooters neglect a caliber out of some form of loyalty to what they normally shoot. We hope that this article has made clear that both of these calibers can be effective when used in the correct situation. There is no law to having rifles chambered for both and in doing so, you greatly open up your shooting world to new opportunities.