.243 Win vs .308 Win – Cartridge Comparison

Gun nuts, hunters, competitive shooters, and people who are a mixture of all three are constantly looking at the wide selection of cartridges available and trying to determine which is more useful. All cartridges are going to have a specific niche in the shooting world where they excel compared to others, but it’s always a fun and informative exercise to put two cartridges up against one another. In this case, it’s the .243 vs the .308.

In this article, we will be taking a look at two very popular cartridges in the US and the world, the .243 Win and .308 Win. These rounds have been on the market for over 50 years, and there is no reason why they won’t continue to be a mainstay in small firearm ammunition.

We are going to make a lot of comparisons on these two cartridges. In the end, we are not going to try to make a claim for which is the best. It’s all relative in our eyes to the situation they are being used in is going to determine which is better suited.

We will take a look at several ballistic categories and performance specs important for hunting and general shooting and discuss the similarities and differences between the two. From there, we can discuss the applications for each cartridge and under which situations they will be better suited.

A Brief History

.308 Winchester

The .308 Winchester was introduced by Winchester in 1952. Though the predecessor, this cartridge is the civilian version of the 7.62×51 NATO round that saw brief use in Vietnam before being replaced, but it still has a niche in military and other tactical communities even today.

Where the .308 has gained a strong and loyal following is in the hunting community. This is a larger bullet with excellent range and stopping power. It’s a great medium to large game rifle and can be used for just about any large game animal in the world, barring a few.

Not only is the .308 a fantastic civilian hunting round, but it also displays enough speed, power, and distance to be adapted into police force sharpshooting units. That is a high recommendation for the use of this cartridge.

The .308 is extremely popular, and you can tell based on the sheer amount of ammunition and type of ammunition that is available. There are several bullet weights, powder charges, and bullet design can all impact the bullets flight and power characteristics.

.243 Winchester

The parent case of the .243 is the other cartridge of discussion in this article, the .308. There are some key differences between the two modern cases. The .243 is a necked down version of the .308 which allows it to take the smaller diameter bullet, the .243. Sometimes referred to as the little brother of the .308, which we are sure it doesn’t appreciate, it is important not to let that comparison influence how these two cartridges perform. As we will see, there might be some big differences between what the two siblings are good at.

Regardless, we will see that there are quite a few similarities between these two rounds which can be attributed to the .243 being a modification of the .308.

The .243 comes in a wide range of bullet sizes and makes it a pretty versatile gun in the hunting world for the type of game it can effectively be used against. It was initially a varmint hunting gun, but the arrival of larger grain bullets and more powerful charges providing more velocity allowed this round to be adapted to larger game such as deer. It pretty much limits out with deer regarding large game hunting as we will discuss in this article. The .243 Win also has a pretty rich history in the long range shooting community. And while newer and flashier rounds have come onto the scene, some of the top shooters in the world still load a .243 and they win with that cartridge consistently.

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Specs

By looking at the case and bullet dimensions, we can immediately begin to make assumptions about these two cartridges. Because the parent case of the .243 is the .308 Winchester, these cartridges have some similarities, but as we will see, there are also a lot of differences. The most noticeable difference is in the neck diameter where the .308 is much wider to fit the larger caliber bullet. We also see that the .308 can withstand higher pressures than the .243 Win which allows the .308 to run a little hotter. For the heavier bullets that the .308 uses, it’s going to need a little more force to get those bullets at the speed needed for proper terminal ballistics The .243 is also longer than the .308 and cannot handle as high an internal pressure as the .308 Win.

Besides those differences, these two cartridges have very similar case dimensions such as the base diameter, case length, overall length, and the case capacity. To see how these two cartridges stack up against each other we have chosen ten factory rounds, five for each cartridge type, and those are listed below.

And we are aware that there are a lot of other options that are on the market and there is a good chance that a round you use and has served you well might not be present. This list is not composed of rounds that we think are superior to all others. We chose these to get a nice, diverse selection of rounds with differences in several aspects within each cartridge type.

As you can see, we are only comparing a limited number of different rounds for each cartridge. While we are selecting a variety of rounds with a good range of bullet weights and designs, it’s only scratching the surface. There is a lot more to a good hunting and competition rounds, but with limited time and space, our selections for comparison will give you an excellent starting point and base of knowledge to dive even deeper into the discussion.

And because there is always the chance that using such a small sample size might not give us a fair representation of the entire set of options that are out there, we have compiled the data for more rounds. At the end of each section, we will present the averages for the larger sample size and discuss the results briefly. For the sake of clarity, we are not going to graph all of that data, but it should show that the selections we have made is a fair representation. And if it doesn’t, we will discuss why. All of the rounds we have compiled are listed at the end of the article.

It’s also important to note that these are all factory rounds and they are not going to have the performance of hot hand loaded rounds that you might come across on other sites or forums. We chose to stick only to factory loads because the majority of people do not handload and that information would not be useful to a lot of people.

Finally, before you jump into the comparisons, we want to make clear where this data is coming from.

The majority of the data is available from the manufacturer, and where that was not available, we relied on ballistic calculators from trusted sources. Where ballistic calculators are used we kept as many variables the same between rounds of the same cartridge. Where calculations are made, we will be sure to make clear our variables.

When it comes to this type of data, there is no concern with comparing cartridges, but you should be aware that these numbers can change when being fired from your rifle. Each rifle tends to have its own small differences in its profile, and this means some small differences in the ballistic output. As far as comparing the two cartridges go, computer generated data has its advantages in that these small differences are negated.

So, with all of that out of the way, let’s get into the fun stuff.

Recoil

This section is as clear of a decision as any other category we will discuss on the .243 vs .308. When most of us think of recoil, we think of the actual kick that is felt when the gun is fired. A lot of factors go into the actual “felt recoil” that we can’t put numbers on for comparison. Instead, we are going to look at the actual energy(ft.lbs) that is created when the power is ignited.

There are several factors that influence the recoil energy. When the data was calculated we used the muzzle velocity for each round, the bullet weight, the gun weight, and the powder charge. We kept the gun weight constant at 7lbs and used the average for several popular powder brands provided by Nosler load data for each cartridge. So while the numbers we present might fluctuate depending on the actual powder charge used by the manufacturer (not provided) or what your rifle weighs, the general trends are safe to draw conclusions from.

So, before we look at the ten rounds, let’s take a general look at the recoil energy generated by the two cartridges (Graph 1).

There is no debate on this category when comparing the .243 and .308 cartridges. The .308 kicks like a mule compared to the .243. With nine ft.lbs of difference between the two, even an experienced shooter is going to feel the difference between these two cartridges.

Of course, the energy generated is going to vary from round to round even within the same cartridge type.

In this graph, we take a look at our ten rounds and see how they compare and if the same trend continues from what we saw in the previous graph. (Graph 2).

Again, you can see that there is some deviation between the rounds of the same cartridge types. Also, keep in mind that some of these rounds might have less or more powder when used in reality, so the recoil energy may vary a little. Regardless, you can easily visualize the greater recoil energy that is produced by the .308 rounds on a consistent basis. All of the .308 rounds are generating more than 20ft.lbs of energy which is considered enough to influence the shot if you are not experienced with the round. On the other hand, the .243 rounds come in between 8 and 12ft.lbs of energy.

The above numbers indicate quite a significant difference between these two cartridges. And while we are confident that this result is indicative of how much recoil energy will be produced by any selection of factory loads available, we still want to look at the recoil data from our larger data set. You will find the data in the table below and note that the recoil data was generated using the same variables that we discussed earlier.

Average Recoil (ft.lb)

So when we increase the amount of samples that we have, we are still seeing the same disparity between the two cartridges. On average, the .308 Winchester is producing right around eleven more ft.lbs of force than the .243 Win rounds. And there is no overlap between these two cartridges. Any factory load you get for the .308 Win is going to produce more recoil than a .243 Win round. Now, the numbers might be a little closer depending on your rifle, but this trend is not surprising given what we know just from the cartridge specs alone.

We also have to be careful about making claims about performance just from the recoil. While the .308 Win produces more recoil, it’s a good indicator that there are going to be other differences between these two cartridges and more recoil might just be something you have to deal with if you want the other performance specs of the .308.

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Ballistics

In the ballistics section, we will focus on the differences in velocity, ballistic coefficients, and trajectory. With this information, we can begin teasing apart where these cartridges would be better suited.

Ballistics is an important concept for anyone shooting a rifle, regardless of the application, but they can also be complicated by a lot of factors influencing each performance category. As we go through these various categories, keep in mind that they all play off of one another and all influence the performance and profile of each round. We look and compare each individually for the sake of simplicity, but all factor into the performance of the bullet and the cartridge as a whole.

Velocity

It’s not as simple as using higher burning powders as these cartridges can only hold so much and take so much pressure, and there is a fine line you walk with a hot round. If paired with the wrong twist rate, the bullet is going to be unstable in the air. For factory loads, you often don’t have to worry about this concept.

There are several reasons to look at the bullet velocity from the muzzle as it moves downrange. The velocity of the bullet is going to play a major role in the trajectory, which in turn, is going to determine the number of adjustments needed to make when taking shots at extended ranges. Velocity is also important in the terminal ballistics of a round as it influences the bullet’s energy as well as how the bullet will expand on impact.

We compiled the velocities of the ten rounds from the manufacture and have graphed them here (Graph 3).

We are looking at the velocity (ft.sec) from the muzzle out to 500 yards in 100-yard increments.

There are several interesting talking points we can harp on from this graph. The first is that the .243 seems to have higher velocities from the muzzle out to the 500-yard mark. The averages all support this though the .308 closes the difference as the rounds move downrange. One of the biggest reasons for this is how quickly the 55gr .243 rounds bleed off velocity. They come out with nearly 4,000ft.sec velocity and they maintain a distinct advantage until the 500-yard mark where all of the rounds begin to group much more tightly.

There is some overlap in velocities between the two cartridges as they reach the 200-yard mark and beyond as it appears that the .243 rounds bleed of velocity at a higher rate than the .308 rounds. All of these rounds maintain supersonic speeds out to 500 rounds and probably will for another several hundred yards.

Let’s take a look at the larger sample set and see if we can get a more definitive look at how these two cartridges compare in their bullet velocities.

Average Velocity (ft/s)

We again see that the .243 Win rounds come out of the muzzle with significantly more velocity than the .308 Win rounds with almost 500 fps difference. And like the small sample size, we also see that the .243 rounds bleed velocity at a higher rate than the .308 Win rounds where there is only a little over 100fps difference between the two at the 500 yard mark. And if you are thinking that extra light .243 rounds (under 60gr) are skewing the data, the average muzzle velocity with those two rounds removed is 3140fps and the 500 yard average is 1900fps. So, they do influence the average, but not as much as you probably think. We were curious about this as well and had to go back in and double check.

Average Supersonic Limit (Yards)

Since we are looking at two cartridges that definitely have the potential for long range shooting, we want to look at what the average cut off is for these cartridges where they drop below supersonic speeds. For hunting purposes, this shouldn’t have as much an impact on your decision making since responsible hunters are not taking shots at this distance with these cartridges.

Marksmen are concerned with supersonic limits because once bullets fall below this speed, they start to become a lot less stable which makes adjusting for shots more difficult. When we look at these two cartridges, there is some about 70 yards difference in the average limit. There are .243 rounds that maintain supersonic speed through the 1,000 yard mark and there are .308 rounds that fall below supersonic speeds closer to the 700 yard mark. There is quite a wide range for both of these cartridges.

We also have to weigh the impact the light .243 varmint rounds are having on this average as we did with the velocity. While they are very fast rounds, we saw that they bled velocity quickly. We still include them because this is a comparison of two cartridges and not of just individual rounds. The varmint rounds are not throwing too big a wrench into these numbers though as we only included two of these lighter rounds (under 60gr) into the data set. And if we take them out, the average only increased to 963 yards.

So these rounds are not influencing these averages any more than a lot of the other rounds do. Still, because they are different from other .243 Win rounds, we will keep an eye on them as we move into other categories.

Ballistic Coefficient

The BC is simply a rating that is derived from an equation that uses multiple cartridge/bullet variables. What this number tells you is how well the bullet resists wind drag and wind drift throughout its flight path and gives you an idea of how well a bullet will be able to cut through air and wind resistance. The higher the ballistic coefficient, the less drag, and influence this resistance will have on the traveling bullet. For shots taken at extended ranges, a higher BC often means fewer adjustments will have to be made to get the bullet on target. The ballistic coefficient is not everything when it comes to having a true flying bullet. While we think it has a large role in making difficult shots easier, don’t make the error of thinking that if a bullet has a high BC, it is going to do all the work for you or replace experience and skill.

Often, the ballistic coefficient is given more attention with long range shooters, but we think it can be important for hunters as well. While hunters might not be taking shots at distances where they need to be worried about the bullets wind and drag resistance, it can’t hurt to know as much about your cartridge as possible.

We have compiled the ballistic coefficients for all ten of the selected rounds and graphed them here (Graph 4).

When we look at the BCs of these two rounds we see that the .308 round, at least from this selection of rounds, has higher ballistic coefficients. There are .308 rounds with lower BCs that look more like the .243 rounds, but there are also rounds with close to double the BCs of some .243 rounds. Generally, increased mass of the bullet increases its ballistic coefficient, given their body design and caliber are similar, and we see that the .308 cartridges uses heavier bullets than the .243 Win cartridge.

So there is some variability within each cartridge type, but generally, .308 rounds are going to have higher BCs.

Just to be sure, let’s take a look at the averages when we add more sample rounds.

Average Ballistic Coefficient

We mentioned earlier that there are rounds where the ballistic coefficient is a bit closer between these cartridges, but overall, the averages give an advantage to the .308 Win rounds. Any data set that you work with is going to have outliers and the .243 Win rounds do have several of those. especially the very light varmint rounds which bring down the .243 Win BC average slightly. Even when we take out those rounds, the average BC for the .243 Win only increases to 0.35 which is still enough difference between the .308 average to warrant discussion later.

Trajectory

It doesn’t matter what you are using a rifle for or what cartridge you are using. The trajectory of the bullet is often one of the most discussed and scrutinized ballistic components. As bullets move downrange, they have a flight path of a parabola. As the bullets lose velocity and as outside influences act on the bullet, it loses altitude. For a cartridge comparison such as the .243 vs .308, potential users want to see which has a flatter trajectory, meaning it shows less bullet drop.

Before we look at specific ranges with the short and long-range trajectory, we want to step back and just look at two rounds, one from each cartridge type, that are similar in bullet weight, BC, and bullet design. Hopefully, this begins to give us an uncluttered look at how the trajectories of these two cartridges compare (Graph 5).

Just because of the nature of these two cartridges, there is some difference between the bullet weights of these two rounds that we have no control over.

We see that there is less than an inch of difference in bullet drop between these two rounds out to the 350-yard mark. From this point, the gap does widen slightly with the .243 round continuing to show a slightly less pronounced drop in trajectory than the .308 round. Even so, the biggest difference in trajectory is not until the 500-yard mark where we re only looking at five inches of difference, at the most.

While the .308 is using much heavier bullets than the .243, they are also using more powder to propel them downrange. So even though the light .243 rounds has a slightly flatter trajectory than the .308, it’s not as pronounced as one might think.

Let’s increase the number of rounds we are comparing and see if this trend continues.

Short Range Trajectory

Both of these cartridges are very popular whitetail cartridges, among other medium sized game, and in these scenarios, the majority of shots are coming at ranges up to 300 yards. Because of this, we want to compare the short-range trajectories of our selected ten rounds.

We compiled data from the manufacturer when available and also from ballistic calculators. To generate data from a ballistic calculator we used the rounds BC, muzzle velocity, and bullet weight (Graph 6).

With the short range trajectory, we do see some patterns regarding cartridge type. The .243 rounds have the flattest performing rounds with the 55 and 58gr bullets. Even barring those two rounds, all of the .243 rounds show a flatter trajectory than the .308 rounds though the difference is minimal at the 200-yard mark. At this point, there is less than two inches difference between the averages of the two cartridges, and if we omitted the two light .243 rounds, there is less than one inch. Regardless of the difference, every round shows less than 5 inches of bullet drop at the 200-yard mark.

The same trend continues at the 300-yard mark. We do see the rounds begin to distance themselves from each other a bit more. Like at the 200-yard mark, the lightweight .243 rounds are nearly five inches flatter than the next closest round. Even the steeper dropping .243 rounds are 2-3 inches flatter than all but one of the .308 rounds. At this point, the averages for both cartridges is 9.72 inches for the .243 and 14.68 for the .308.

Let’s take a look at the short range numbers when we add more rounds, especially with the .243 Win rounds with heavier bullet weights.

Average Bullet Drop (Inches) at Short Range

We still see the same trend here, with the .243 rounds showing several inches less bullet drop than the .308 Win rounds. There is not a huge difference between the two at the 200 and 300 yard mark, and we are still only looking at about 8 inches of difference between the two when we go out further at 400 yards, which is pretty impressive given the much heavier bullet weights of the .308 Win rounds. Of course, you’re also dealing with a lot more recoil, as we saw earlier. There are always trade offs when trying to decide between two cartridges or even just two different rounds.

These are the ranges that are most often encountered in hunting scenarios. And we realize that most of you are already aware of what we are about to say, but trajectory is far from the only performance spec that needs to be considered when thinking about a cartridge you are wanting to use. So don’t close out the article yet thinking the .243 Win is what you need. We’ll get into some other important performance factors for hunting shortly.

Long Range Trajectory

While neither of these rounds is considered top long-range rounds in today’s shooting world, they are still options and are used by a lot of people. Because of that, we will take a look at these rounds long-range trajectories.

Data were acquired in the same manner as the short range trajectory, but we carried the graph out to 500 yards (Graph 7).

Overall, we see a similar trend as we did with the short range trajectory. Besides the two lightweight .243 rounds, we see tight groupings of all the other rounds at the 300 and 400-yard marks.

As the rounds move out to the 500-yard mark, we do see a distinct advantage in trajectory for the .243 rounds. There are several .308 rounds that cluster more tightly with the steeper .243 rounds, but overall the difference in averages is pretty clear. The .243 has an average bullet drop at 500 yards of 38 inches while the .308 has an average of 50 inches.

Let’s take a look at the long range averages for these two cartridges and see if the trend holds up with more rounds thrown into the mix. We have also extended this comparison out with a 700 and 1000 yard marker.

Average Bullet Drop (Inches) at Long Range

When we look at the data for the larger data set, we do see the .243 Win cartridge has a flatter trajectory throughout the entire range. We also see that as the distance increases, the difference between the two cartridges increases. Compared to the ranges that we used with the smaller sample, the difference between the two rounds is not large but still apparent. Where we start to see major differences in the performance of these cartridge is at the 700 yard mark and beyond. At these two markers, we see right around 20 to 30 inches separating the two cartridges. (20.9 at 700 yards and 28.6 at 1000 yards). And while the .308 trajectory is still impressive given that bullets sometimes twice the weight or more than the .243 Win rounds, this is a distinct advantage for the .243 Win in long range trajectory.

And while the .243 might appear to be a clear-cut winner there is more that you have to consider depending on what you are doing. Especially if it is hunting, where stopping power is as critical and is the subject of our next section.

Stopping Power

These two cartridges are not often used in home defense settings, so we will focus on knockdown power regarding hunting scenarios. While the .308 does have a history in tactical applications as well, it is not often enough for us to focus on that area either, especially with our second cartridge being the .243 Win.

While hunting, being able to have confidence that your bullet will reach the target and still have enough force to make a clean and quick harvest does a lot for confidence. We will look at the stopping power of these two cartridges by looking at three different metrics which include kinetic energy, sectional density, bullet momentum. The latter two are ways to determine how well a round will penetrate.

These are not the sole factors involved in stopping power. These are simply the best metrics we have when it comes to the type of data we are using. They are still important components to stopping power as well are the components we are not going to discuss here. Some of which include bullet design, which influences penetration and wound type, and perhaps the most important component to stopping power, shot placement. None of the other components do us much good if the round isn’t put where it can do some damage.

Because stopping power is a culmination of a lot of different factors, we don’t ever try to get into the argument of which metric is the best indicator of a rounds stopping power. All of the different metrics play a role and provide us with different but equally important information.

Energy

The energy or force (ft.lb) that is associated with a bullet on its flight path is transferred to the target on impact and can cause a tremendous amount of damage to surrounding tissue and organs which makes this component of stopping power important to examine. You will often see the loose guidelines for how much energy is needed to harvest specific animals. For most medium size game, 1,000ft.lbs of energy is the recommended amount, and this increases the larger the animal gets.

For the two cartridges we are looking at, they are very popular whitetail and other medium-sized game. Although, the .308 might have other applications that we will look at later.

While we agree that energy is important, we also think shot placement is as important if not more. It’s also important to remember that expansion of the bullet is also important is this allows the maximum amount of energy to transfer to the target.

So, let’s take a look at our ten rounds and see how the kinetic energy differs between these two cartridges (Graph 8).

The differences in bullet energy between these two rounds is obvious. Rounds of each cartridges cluster tightly together through the 500 yards with the .308 showing significantly more bullet energy than the .243.

From the muzzle, we are looking at nearly a 1,000ft.lbs difference in the averages of the two cartridges. The difference shrinks as the rounds move downrange but the advantage still clearly belongs to the .308 rounds. And we would expect this trend given the similarities in velocity between the rounds, barring the two lightweight .243 rounds, and the increased bullet weights of the .308 rounds.

At the muzzle, the .308 rounds have bullet energies above 2,500ft.lbs, and all remain between 1,000 and 1,400ft.lbs at the 500-yard mark. The .243 rounds all have muzzle energies between 1,700 and 2,000ft.lbs at the muzzle but drop below the 1,000ft.lb mark by 400 yards. This information is going to be useful when we discuss the applications of these rounds.

With such a disparity between these two cartridges, let’s take a look at more rounds and see if the gap widens or closes.

Average Bullet Kinetic Energy (ft.lbs)

When we expand our sample size, we still see that the .308 Win rounds carry quite a bit more kinetic energy downrange than the .243 Win rounds, though we do see the difference shrink by a few hundred ft.lbs than what we saw in the graph above. There is still a large difference though and it is substantial enough to take note of and take into account when thinking about which applications these cartridges would be better suited for.

We do see that the .308 Win rounds still carry over 1,000ft.lbs through the 500 yard mark while the .243 Win rounds begin falling below this threshold at the 300 yard mark. And again, this might or might not matter to you based on the type of hunting you have in mind.

Penetration (Sectional Density)

To get an idea of how well these two cartridges can penetrate a target, we will look at the sectional densities (SD) of the same rounds we have been using for comparison in this article. We do want to note, that not all hunting or shooting scenarios call for a large amount of penetration. It goes with what we have been saying from the beginning, that there is not clear cut winner and both provide the performance you need for certain hunting and shooting applications.

The SD is derived from the bullet’s weight and diameter. The higher the SD of the bullet, the deeper it should be able to penetrate. SD along with velocity and bullet type all factor into penetration, and we will discuss how it all ties together in the application section. Our next metric, bullet momentum, is also intrinsically tied with the sectional density when it comes to penetration.

Just to try and have a better understanding of how exactly this number we calculate has anything to do with how well a bullet will penetrate. Let’s look at a crude example. We have bullet A at 100gr and a .300 bullet diameter. We also have bullet B which is also 100gr but with a .200 bullet diameter. We are also assuming that all other qualities of the round are identical. The sectional density for bullet B is going to be greater than for bullet A. Bullet B should also penetrate deeper. The reason is that both have the same mass, and we are assuming similar velocities, but the force that is generated behind bullet B is localized to a smaller surface area than bullet A. Imagine taking a hammer and driving a railroad spike into the ground compared to a 2×4. This is the theory behind sectional density.

If we look at the SDs of the ten rounds, which we calculated using an SD calculator (Graph 9) we see that there are some differences between these two cartridges.

First, there are some distinct differences just between the .243 rounds. We see that the lightweight .243 rounds have a significantly smaller SD than the heavier .243 rounds.

If we look at the heavier .243 rounds, there is not a whole lot of difference between the .308 rounds. All of the .308 rounds still have higher SDs, but their sectional densities are only around 1-3 hundredths more.

While the .243 has a smaller diameter, the heavier .308 rounds are the reason their sectional density is greater. And this information is going to let us tease the hunting applications of these two cartridges in a few moments.

Average Sectional Density

When we look at the numbers for the larger data set, we see the same trend that we just observed for the smaller data set. While the .243 Win rounds have an average that is only about 3 one hundredths behind the .308 Win rounds, this is quite a bit for sectional density. And while there are also several .243 rounds that have a sectional density closer to the .308 average and there are a couple .308 rounds that do not have as high a sectional density as some .243 Win rounds, you are generally going to have more options for high sectional densities with the .308 Win.

You guys have to be tired of hearing us say this, but you also can’t forget that we are not bringing bullet design into the equation. You can have a high sectional density, but if the bullet is going to break apart, a round with a lower sectional density but a bonded jacket, in the end, is going to penetrate deeper. You have to love the depth and variables involved with this topic. It gives you a lifetime of opportunities for learning.

Penetration (Momentum)

The final metric that we will look at for stopping power is bullet momentum. What we are trying to get an idea of is how well can these bullets overcome resistance. From a hunting perspective, how well will these bullets penetrate. Momentum is tied in with sectional density because of the idea of resistance. Higher sectional densities generally mean that less resistance is being encountered or there is at least enough force behind the bullet to overcome the resistance.

So for momentum, the higher the number, the more resistance the bullet can encounter while still moving forward. That is the definition of momentum, the ability of an object in motion to stay in motion.

We calculated the momentum of the selected rounds and graphed those numbers from the muzzle out to 500 yards (Graph 10).

Like the kinetic energy, we see a significant difference in the momentum between these two cartridges. And that seems to be a trend between these two cartridges when looking at how they compare in the components of stopping power. And that’s not to say the .243 Win is not a lethal round for game, but the numbers show that the .308 Win is much better suited when tackling larger game and the majority of hunters would agree with us.

We definitely see from this graph that these two cartridges look to behave differently. We see that the rounds of each specific cartridge group pretty tightly together though the .243 rounds seem to split into two groups.

As you can probably guess just by looking at the chart, the two rounds with the lowest bullet momentum are the 55 and 58gr rounds. Even with the heavier .243 Win rounds, there is still a very significant gap between them and the .308 Win round with the lowest momentum.
We see that all of the .308 Win rounds leave the muzzle with over 60lbs/ft.s of momentum, several closer to 70, while the .243 rounds, besides the 55 and 58gr rounds, hover near the 40lbs/ft.s mark. This difference between the cartridges remains the same as the rounds move downrange though the amount of difference between the two cartridges does drop to only 17lbs/ft.s when we don’t include the 55 and 58gr rounds.

Let’s look at the bullet momentum averages when more rounds are added into the equation.

Average Bullet Momentum (lb/ft.s)

Just like the smaller sample size, the .308 Win rounds generate nearly 25 more lbs/ft.s from the muzzle to 17 more out at 500 yards. The .308 Win rounds do seem to bleed of momentum at a higher rate, which is also what we saw earlier, but they are still carrying significantly more at ranges where most hunting shots are taken.

Accuracy

This is another point of comparison with the .243 vs .308 that a lot of hunters or marksman often search for when trying to decide on a cartridge. The honest truth is, accuracy is often more linked to the firearm, the optics, and the user’s ability. Though, the ballistics can make a difference when the two cartridges are being shot by someone who knows what they are doing.

Within 200 yards, both of these cartridges can be nail drivers given their trajectory at these ranges. Once you move out to longer ranges, the .243 showed a slight advantage over the .308 with a less pronounced bullet drop. Now, there was a much greater advantage to the lightweight .243 rounds, but if they will not be suitable for certain applications, there were .308 rounds that were very similar to the heavier .243 rounds.

We did see a slight advantage in the ballistic coefficients of the .308 rounds. So while the bullet drop might be more pronounced, the BC and heavier weight of the .308 might help it resist other environmental factors such as wind, when taking long range shots compared to the .243.

The recoil of the .308 could reduce accuracy for novice shooters compared to a .243. We were looking at nearly double the recoil energy of the .308 compared to some .243 rounds. This is enough difference and enough recoil for the .308 to throw off shots during the pull.

With the .308, you can get up to some pretty heavy bullet sizes, and the twist rate of your rifle could impact the accuracy of the round. This will only be the case if you are using a heavy bullet with a rifle with a slow twist rate. Having the correct twist rate will stabilize the bullet as it moves through the air. Poor stabilization can throw off the trajectory that you have sent the bullet on. And the same goes for .243 rounds though the issue often arises when handloading the cartridge too hot. This is not something we discussed in the article, but it is something to keep in mind.

Again, regarding the actual cartridges along with their case and bullet design, the differences in accuracy are non-existent. It is just going to depend on the skill of the user and environmental conditions.

Price and Availability

Both of these cartridges are fairly prevalent on the market. For any major retailer, they are going to have both .243 and .308 rounds in stock and usually have a variety of options for both cartridges. A lot is also going to depend on the area you are in. The internet has made it much easier to find the specific round of either cartridge you fall in love with, but often these rarer cartridges are going to cost a pretty penny.

Regarding price, the .243 round is on average cheaper than the .308. It all depends on the quality of the cartridge as well. There are cheaper versions of each cartridge available in bulk while high-end rounds are both going to be pretty expensive regardless of the cartridge. For a 20 round box of .308 rounds that are reliable enough to be used in the field, you’re looking at around $35 on average. For the .243, you’re looking more at an average price of $30 for a box of 20 rounds. Like the .308, a box of .243 cartridges can vary from $20 to $50 bucks.

Overall, the price of these cartridges is not very different. Not enough to choose one of the other based solely on price in our eyes.

Applications

So, now that we have a good basis of comparisons of the .243 vs .308, we can take a look at situations where one cartridge might be favored over the other.

The .308 is often described as a great short range cartridge for whitetail and other larger game. The reason for this is the energy behind the bullet as well as the penetration it can attain. You have a much better chance of hitting a little brush and still be able to punch the bullet home on the target and the high momentum of the bullet’s helps it in this regard. A lot of this also has to do with the rifles chambered It’s much more than just a short range cartridge. You can easily use this to take shots at 300+ yards. With heavier bullets, you will have to compensate for elevation loss, but you can always improve this by going with a slightly lighter bullet or higher pressured round.

The .308 has excellent stopping power, when we look at the energy and potential penetration and with some careful considerations on cartridge type, the .308 can take down just about any large game in the US and world at a variety of ranges. The .308 has a bit of a kick, especially when compared to the .243 and might be a bit much for users that don’t have much experience with firearms.

The .243 serves well in several roles as well when it comes to hunting. The .243 is a light and high-velocity cartridge that is one of the best for varmint and predator hunting. By increasing the bullet weight, you also have a tremendous whitetail cartridge as well that we think is just as efficient as the .308 with its high velocity and penetration. It doesn’t have near the bullet momentum as the .308 but for applications this cartridge is normally used for, you really don’t need it. Whitetail do not have the thick hide or bone structure that is going to require a lot more momentum to punch through cleanly. While this cartridge has decent range, it just loses too much energy to take larger game at far distances unless it’s the perfect shot, and even then it might just result in a wounded animal.

The .243 ammunition is cheaper than the .308, and it’s flat trajectory and high speeds make it a fun and affordable round to use on the range. The lack of recoil also makes it a great firearm to introduce new or young hunters/marksmen to the sport.

When it comes to long-range shooting with these rounds, there are pros and cons to each. And again, we are not talking about handloading here, strictly factory loads. There is the issue of recoil, which we talk a little more about shortly, but we want to focus on the ballistics. The differences in velocity between these rounds depends on the individual round. The .243 has options for some hot rounds, but the hot ones, bleed velocity quickly and by the time you get out to 500 yards there is not much difference. The .243 rounds have an advantage in trajectory, but their lightweight bullets are going to be affected by wind more so than the heavier .308 rounds which also have slightly better BCs overall and sometimes a large advantage.

If you have a decent amount of experience with firearms, the .308 recoil is probably nothing that would deter you from using it. With a decent recoil pad and proper shooting position, the recoil is manageable for adults. Where it may cause some pause when considering the .308 based on recoil is if it is for someone just getting into shooting and hunting or a younger outdoorsman.

You just have to have experience shooting these different rounds of the two cartridges to get a feel of what is too much recoil for you to shoot comfortably.

Best Rounds

Before we wrap up this article, we want to look back at the ten rounds we have been comparing throughout this debate and make a few selections for rounds, from each cartridge, that we think are well suited for specific tasks. This is just our opinion, and we think there are quite a few rounds, those not on our list as well, that can do just as well as the rounds we are going to pick. At the end of the day, we think the best round is the one you are confident in and the one that has brought you success consistently.

Top Hunting Round

For the .308 Win, we like the Nosler Ballistic Tip 165gr. This is another excellent option for medium to larger game. The bullet energy is the highest of the selected .308 rounds with 1,300ft.lbs of energy at the 500-yard mark which is enough for even larger game at that range. With proper shot placement, this round still has the energy and the velocity to make a clean kill. Anything within that yard mark is no issue. For the .308 rounds, it has one of the best long-range trajectories where a 300-yard shot is no problem in the right hands, and 400 yards is even manageable.

For the .243, we are big advocates of the Federal Vital-Shok Nosler Ballistic Tip 95gr. The Nosler Ballistic Tip bullet is one of our favorites for deer sized game. This cartridge provides incredible trajectories with only 3″ of bullet drop at 200 yards. More importantly, this round maintains the velocities to cause sufficient penetration and expansion, and it carries more than enough stopping power out to 300 yards which is excellent for a .243 hunting round at this weight.

Top Range Round

For our top .308 Win range round we like the 168gr Hornady BTHP Match. This round is affordable which is an important consideration when you plan burning through quite a few out on the range. This round has a great BC for .308 rounds (.45), and when paired with the velocity and long-range trajectory, you have an excellent round for precision shooting.

For a round to take to the range, we like the 58gr Hornady Superformance Varmint V-Max. This round has high velocities, but it does bleed off speed at a high rate, and by the time you get out to 500 yards and beyond, it doesn’t perform any better than other rounds regarding velocity. It does shine when it comes to trajectory. The bullet drop on this round is second to none when it comes to .243 factory loads. It is lightweight with very little recoil, so it’s fun to shoot all day with little fatigue. It’s fairly inexpensive compared to other rounds with similar performance. It is lightweight and might be more influenced by drag and wind drift if you are looking at shots at 500+ yards. It might not be a competition round, but it is fun to mess around with while on the range with friends.

Conclusion

When looking at the .243 vs .308 cartridges, there are certain situations where one cartridge excels over the other, but it all depends on the circumstances and your personal preferences as to which you enjoy shooting and are more comfortable and confident with using.

Both the .243 and the .308 are tremendous cartridges that are widely abundant to come by and are pretty versatile when it comes to different shooting scenarios. We hope that this article has provided a more detailed comparison between the two cartridges and given you a much stronger foundation to base your decision on.

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