7.62×39 vs 308 – 2022 Assessment

The 7.62×39 mm gains its recognition by being the cartridge used in the venerable and legendary AK-47 assault rifle. While this cartridge was being developed in the Soviet Union, the United States of America was working on a round to replace the .30-06 Springfield. The result was the 7.62×51 NATO, and Winchester picked it up in 1952 and introduced a civilian version which is known as the .308 Winchester. A name that every firearm owner admires and probably owns. 

This guide will compare these two rounds, and try to evaluate if one is better than the other. It will give you a detailed idea of the advantages and shortcomings of these rounds, and help decide which of these to pick on a given occasion. 

TL;DR: 7.62×39 vs 308

Here’s a quick peek into the pros and cons of these two rounds.

7.62×39 Overview

The 7.62×39 mm is a rimless, bottlenecked, intermediate rifle cartridge that is among the widely used cartridges of today. This is the round that the AK-47 is chambered for, and other popular rifles include the SKS and RPD machine gun. 

This round was designed in 1943 in the Soviet Union under a committee of designers led by N.M Elizarov and later adopted in 1948-49 for the AK-47 rifles. This cartridge went through a lot of to and fro in designs, but the final version was found perfect for small arms and light machine guns at the time. Even to this day, many militias around the world use AK-47s and this round. 

A big chunk of those have been replaced by the AK-74 and later versions of the AK which fire the 5.45×39 mm cartridge. However, the 7.62×39 mm still stays in active service with the Russian and several other militaries around the world. 

As far as civilian rounds are concerned, this cartridge is comparable with the  .30/30 Winchester. The high and easy availability of dirt-cheap ammunition makes it an insanely popular rifle among plinkers and some hunters. 

308 Overview

The .308 Winchester a.k.a the .308 or .308 Win is a rimless, bottlenecked, rifle cartridge that is considered to be the most popular hunting round across the world. It can be seen as the civilian version of the 7.62×51 NATO cartridge that is widely used in active military service by many countries including NATO nations. 

This round was developed in 1952 when the U.S Military was also experimenting with developing a new cartridge to replace their existing long action .30-06 Springfield service cartridge. The experimental round known as the T65, which was later renamed as the 7.62 NATO was quickly picked up by Winchester and introduced on the civilian market a couple of years ago. 

The .308 Win delivers identical performance to the .30-06 Springfield and has the reputation of being one of the most versatile cartridges to be ever designed. It is also quite popular among the special teams of many police departments as a sniping round. Additionally, rifles like the AR-10 come chambered for this round. 

7.62×39 vs 308: Cartridge Specs

Here’s a quick table comparing the dimensions of these cartridges. 

	7.62×39	.308
Bullet Diameter	0.309-0.312 in	0.308 in (7.8 mm)
Neck Diameter	0.339 in (8.60 mm)	0.3433 in (8.72 mm)
Base Diameter	0.447 in (8.335 mm)	0.4709 in (11.96 mm)
Case Length	1.524 in (38.70 mm)	2.015 in (51.2 mm)
Overall Length	2.205 in (56 mm)	2.800 in (71.1 mm)
Case Capacity	35.6 grains	56 grains
Max Pressure (SAAMI)	45,010 psi	60,191 psi
Typical Casing Material	Steel or Brass	Steel or Brass
Typical Bullet Weight (gr)	123-125 grains	150-180 grains

These two cartridges are somewhat comparable but still differ on a few aspects. The short and long range performance will be evaluated in the further sections, but first, let’s take a look at the dimensions. 

The 7.62×39 mm fires a slightly bigger diameter bullet as compared to the .308 Win. It uses different bullet diameters ranging between 0.309 to 0.312 inches in diameter, and the larger size delivers a slight impact on the power. 

The neck diameter of both these rounds is quite similar, but the overall length differs significantly. The .308 Win is a 2.8 inch long round, compared to the 2.2 inches of the 7.62×39 mm. This gives the AK round a slightly faster rate of cycling in full-auto firearms. 

The shorter size of the 7.62×39 mm also means that it carries lesser power, which is only 35.6 grains compared to the 56 grains of the .308 Win. The .308 Win also uses a 50% higher chamber pressure, which gives it an edge in long range performance. 

The .308 Win uses heavier bullets compared to the 7.62×39 mm. Although sometimes bullet weights can overlap for uncommon loadings, the .308 Win generally has heavier bullets. Both these rounds can be found in steel or brass cased ammo, however, the 7.62×39 is widely available in steel cased variants which are dirt cheap and mostly milsurp. 

7.62×39 vs 308: Ballistics

The study of ballistics for a round covers the aspects of trajectory, speed, and energy for the bullet. These factors help us determine the accuracy, range, and effectiveness of a round at different ranges, and against different types of targets. 

7.62×39 vs 308: Trajectory

Here is a tabular representation of the data related to the trajectory of these rounds out to a distance of 1,000 yards. 

7.62×39

16 barrel/BC 0.274/123 gr JSP	16 barrel/BC 0.298/124 gr FMJ	16 barrel/BC 0.302/150 gr Nosler Accubond
100 yds: 0 “ Drop	100 yds: 0 “ Drop	100 yds: 0 “ Drop
200 yds: 6.7 “ Drop	200 yds: 6.5 “ Drop	200 yds: 8.7 “ Drop
300 yds: 24.6 “ Drop	300 yds: 23.8 “ Drop	300 yds: 30.8 “ Drop
400 yds: 57.4 “ Drop	400 yds: 54.6 “ Drop	400 yds: 70.3 “ Drop
500 yds: 110.4 “ Drop	500 yds: 103.8 “ Drop	500 yds: 132.3 “ Drop
1,000 yds: 849.6 “ Drop	1,000 yds: 791.1 “ Drop	1,000 yds: 1261.6 “ Drop

.308 Win

24”barrel/BC 0.408/150 gr FMJ Boat-tail	24”barrel/BC 0.489/168 gr Berger Hybrid	24”barrel/BC 0.536/175 gr Edge TLR
100 yds: 0 “ Drop	100 yds: 0 “ Drop	100 yds: 0 “ Drop
200 yds: 3.6 “ Drop	200 yds: 4 “ Drop	200 yds: 4.4 “ Drop
300 yds: 13.5 “ Drop	300 yds: 14.4 “ Drop	300 yds: 15.5 “ Drop
400 yds: 30.6 “ Drop	400 yds: 32 “ Drop	400 yds: 34.2 “ Drop
500 yds: 56.3 “ Drop	500 yds: 58 “ Drop	500 yds: 61.5 “ Drop
1,000 yds: 405.5 “ Drop	1,000 yds: 384.2 “ Drop	1,000 yds: 392.5 “ Drop

The rounds used for this comparison are the most common bullets and bullet weights. For example, the 123 grain 7.62×39 mm round is the standard for militaries that use it. Similarly, the 168 grain is the most common bullet weight for the .308 Win. 

A flat-shooting round is preferred for medium and long range adjustments because it requires lesser adjustments on the scope, and the point of impact is more predictable. The 7.62×39 mm shows an average drop of about 24 inches for the most common loads at 300 yards. It has an average drop of about 55 inches at 400 yards, which is somewhat acceptable, but not really good. 

On the other hand, the .308 Win is a significantly flat shooting round that shoots very flat out to 500 yards and has an average drop of just 390 inches at 1,000 yards. These trajectory characteristics qualify it as an amazing long range round. 

The same cannot be said for the 7.62×39 mm as it starts dropping to more than 100 inches at just 500 yards, and has a drop of more than 800 inches at 500 yards. So it is clearly not a long range round and exclusively meant for the short to medium range. Which is clearly not a surprise because it was developed for assault submachines and machine guns. 

7.62×39 vs 308: Velocity & Kinetic Energy

The next important factor we will be talking about are the speed and energy characteristics of these rounds. This will help us decide if these rounds are suitable for hunting, sniping, or any other applications and at what range. 

7.62×39

16 barrel/BC 0.274/123 gr JSP	16 barrel/BC 0.298/124 g FMJ	16 barrel/BC 0.302/150 gr Nosler Accubond
100 yds: 2,055 ft/s, 1,153 ft.lbs	100 yds: 2,078 ft/s, 1,189 ft.lbs	100 yds: 1,849 ft/s, 1,139 ft.lbs
200 yds: 1,783ft/s, 868 ft.lbs	200 yds: 1,824ft/s, 916 ft.lbs	200 yds: 1,620ft/s, 874 ft.lbs
300 yds: 1,539 ft/s, 646 ft.lbs	300 yds: 1,595 ft/s, 701 ft.lbs	300 yds: 1,416 ft/s, 668 ft.lbs
400 yds: 1,329 ft/s, 482 ft.lbs	400 yds: 1,392 ft/s, 533 ft.lbs	400 yds: 1,245 ft/s, 516 ft.lbs
500 yds: 1,164 ft/s, 370 ft.lbs	500 yds: 1,224 ft/s, 412 ft.lbs	500 yds: 1,115 ft/s, 414 ft.lbs
1,000 yds: 819 ft/s, 183 ft.lbs	1,000 yds: 854 ft/s, 201 ft.lbs	1,000 yds: 823 ft/s, 226 ft.lbs

.308 Win

24”barrel/BC 0.408/150 gr FMJ Boat-tail	24”barrel/BC 0.489/168 gr Berger Hybrid	24”barrel/BC 0.536/175 gr Edge TLR
100 yds: 2,597 ft/s, 2,246 ft.lbs	100 yds: 2,518 ft/s, 2,365 ft.lbs	100 yds: 2,437 ft/s, 2,308 ft.lbs
200 yds: 2,385 ft/s, 1894 ft.lbs	200 yds: 2,343 ft/s, 2,048 ft.lbs	200 yds: 2,280 ft/s, 2,021 ft.lbs
300 yds: 2,183 ft/s, 1,586 ft.lbs	300 yds: 2,176 ft/s, 1,766 ft.lbs	300 yds: 2,130 ft/s, 1,762 ft.lbs
400 yds: 1,990 ft/s, 1,319 ft.lbs	400 yds: 2,015 ft/s, 1,514 ft.lbs	400 yds: 1,984 ft/s, 1,530 ft.lbs
500 yds: 1,808 ft/s, 1,089 ft.lbs	500 yds: 1,860 ft/s, 1,291 ft.lbs	500 yds: 1,845 ft/s, 1,322 ft.lbs
1,000 yds: 1,130 ft/s, 425 ft.lbs	1,000 yds: 1,239 ft/s, 573 ft.lbs	1,000 yds: 1,271 ft/s, 628 ft.lbs

The comparison of velocity data shows us that both these rounds stay supersonic out to a significant range. The 7.62×39 mm can stay supersonic out to 500 or even 600 yards with its lightweight bullet but does not have enough power and space to propel beyond that. Being supersonic indicates that the behavior of the bullet is more predictable, however, with a large drop in trajectory beyond 400 yards, this supersonic velocity does not give this round a lot of advantage. 

The .308 Win is also a supersonic round and maintains that speed beyond 1,000 yards, and even up to 1,400 yards with some loads. This makes the round very predictable and combined with the amazing trajectory, this round is great for long range precision applications like competitions or sniping. 

Moving on to the energy characteristics, let me establish a benchmark here to give you a better idea. According to general standards, a minimum of 1,000 fpe of energy is suitable to kill a deer, and 1,500 fpe is suitable for an elk-sized game. 

Taking both these factors into consideration, the 7.62×39 mm seems a suitable cartridge for hunting deer within 150 yards, and it is not meant for harvesting big game humanely. Whereas, the .308 Win can easily harvest elk-sized game out to 350 or even 400 yards, and is also suitable for deer out to 700 yards with the appropriate bullet. 

7.62×39 vs 308: Stopping Power

The stopping power of a bullet is its ability to incapacitate or kill a target as quickly as possible. The two most definitive parameters to evaluate the stopping power of a round are momentum and sectional density. As a matter of fact, being bigger doesn’t always mean that a round will have more stopping power. Please read further to understand what I mean. 

7.62×39 vs 308: Momentum & Sectional Density

Check out the tabular data of the momentum and sectional density values of these two cartridges for a quick side-by-side comparison. 

7.62×39

16 barrel/BC 0.274/123 gr JSP Sectional Density: 0.181	16 barrel/BC 0.298/124 gr FMJ Sectional Density: 0.182	16 barrel/BC 0.302/150 gr Nosler Accubond Sectional Density: 0.220
100 yds: 36 lb.ft-s	100 yds: 36 lb.ft-s	100 yds: 39 lb.ft-s
200 yds: 31 lb.ft-s	200 yds: 32 lb.ft-s	200 yds: 34 lb.ft-s
300 yds: 27 lb.ft-s	300 yds: 28 lb.ft-s	300 yds: 30 lb.ft-s
400 yds: 23 lb.ft-s	400 yds: 24 lb.ft-s	400 yds: 26 lb.ft-s
500 yds: 20 lb.ft-s	500 yds: 21 lb.ft-s	500 yds: 23 lb.ft-s
1,000 yds: 14 lb.ft-s	1,000 yds: 15 lb.ft-s	1,000 yds: 17 lb.ft-s

.308 Win

24”barrel/BC 0.408/150 gr FMJ Boat-tail Sectional Density: 0.266	24”barrel/BC 0.489/168 gr Berger Hybrid Sectional Density: 0.253	24”barrel/BC 0.536/175 gr Edge TLR Sectional Density: 0.264
100 yds: 55 lb.ft-s	100 yds: 60 lb.ft-s	100 yds: 60 lb.ft-s
200 yds: 51 lb.ft-s	200 yds: 56lb.ft-s	200 yds: 57 lb.ft-s
300 yds: 46 lb.ft-s	300 yds: 52 lb.ft-s	300 yds: 53 lb.ft-s
400 yds: 42 lb.ft-s	400 yds: 48 lb.ft-s	400 yds: 49 lb.ft-s
500 yds: 38 lb.ft-s	500 yds: 44 lb.ft-s	500 yds: 46 lb.ft-s
1,000 yds: 24 lb.ft-s	1,000 yds: 26 lb.ft-s	1,000 yds: 27 lb.ft-s

The sectional density (SD) of a bullet is the result of the division of a bullet’s diameter to its mass. The higher this number, the more penetration will be caused by a bullet. For example, an SD of 0.220 to 0.260 is considered best for a deer-sized game, and an SD of 0.261 to 0.300 is suitable for a bigger game like elk. 

Given the sectional density of these rounds, the 7.62×39 mm does not seem to be a great deer hunting round. A big reason for this is also the steel core bullets which do make the projectile stable, but also too stable when tearing tissue. According to a study, the bullet begins to yaw only after moving through 10 inches of tissue. 

Although the data do not concur on the 7.62×39 mm being an effective deer hunting rifle, some hunters have found success with it. However, I will not recommend hunting a deer with it unless you are within 100 yards of your target, or use dedicated ammo. 

The .308 Win is undoubtedly the most popular hunting cartridge in existence today. Hunters have used it to take down game animals of all sizes. The SD values of the loads mentioned above make it suitable for deer, and other loads can be used to take down bigger critters with ease. 

7.62×39 vs 308: Use Cases & Effective Range

Both these rounds stand close to each other in terms of popularity. While each of these was designed to serve a specific purpose, let us understand the best applications for them. 

Small and Medium Game Hunting

The 7.62×39 mm round is a good choice for taking down small game animals and small sizer deer. However, appropriate bullets like the V-Max, SP, or SST should be used for optimal expansion, and the range should be kept inside 100-150 yards. 

The .308 Win is actually overkilled for small game animals and is a perfect deer hunting round. There is a wide range of bullets to choose from, and the power is enough to humanely harvest medium size game. 

Big Game Hunting

The energy and stopping power characteristics clearly indicate that the .308 Win is a more potent round for big game hunting. If it carries enough energy to take down an elk at 500 yards, it can certainly take down a similar sized game within 200 to 300 yards with absolute ease. The 7.62×39 mm on the other hand is not suitable for big game animals due to its low power, however, it does offer good penetration. So comparatively, the .308 Win is the winner for bi game hunting. 

Tactical Applications

The 7.62×39 mm has been used as an assault rifle and light machine gun cartridge for decades now. It is a deadly round within 300 yards, and that makes it perfect for CQB and other combat applications. Although there are better alternatives to it, like the .300 Blk, and 6.5 Creedmoor, the cheap cost and easy maintenance of the AK series of rifles still keeps it popular. 

The military version of the .308 Win, which is the 7.62 NATO, is widely used by many militaries around the world. In fact, rifles like the AR-10 come chambered for this round, so the tactical ability of this round cannot be doubted. Additionally, the .308 Win offers a mix of short and long range, and suppressing power with quick cycling to prove it more versatile. 

Long Range Applications (Sniping/Competitions)

The .308 Win is widely used in competitions, and also as a sniper rifle by the SWAT teams of many police departments. In fact, the 7.62 NATO is a widely used sniper, main rifle, and machine gun round even today. The 7.62×39 mm does not have the appropriate trajectory to work as a long range round because it was not designed to work that way. 

7.62×39 vs 308: Costs, Availability, & Compatibility

One important factor to consider when choosing a cartridge is its ease of availability and if offers ample options in ammo and rifles

Cheap and Abundant

The 7.62×39 mm ammo can be found for dirt cheap prices of about 40 cents per round for steel-cased ammunition. In any case, even the most premium ammo will never cost you more than $3 per round. The .308 Win is also a relatively inexpensive round and every gun shop carries it. The same cannot be said for the 7.62×39 mm, but it is also relatively abundant. The availability of milsurp ammo makes these rounds fairly inexpensive. 

Wide Range of Rifle & Ammo Options

Both these rounds have been around for the same time, and have a number of rifles modeled for them. While the 7.62×39 mm has the AK-47 and SKS rifles, the .308 Win has a lot to offer ranging from the AR-10 to Remington 700;. There are also a wide range of ammo options available for these cartridges.

Bottom Line

The 7.62×39 mm and .308 Win were developed around the same time and for somewhat similar purposes. However, the .308 Win was (or the 7.62 NATO) was seen as a replacement for the .30-06 Springfield, so it had to deliver the long range and power. Whereas, the 7.62×39 mm was designed for short and medium range. 

While the .308 Win is a versatile round suitable for everything, the 7.62×39 mm is limited to close quarter engagements and some hunting.