No two rifle cartridges demand comparison more than 7.62×39 vs 5.56. One is America’s favorite rifle cartridge; the other is Russia’s pride and joy, but hugely popular stateside nonetheless.

Ammo doesn’t have politics and nationalities. We judge a round solely on the quality of its in-flight ballistics, energy, recoil, and price and availability. That’s why we’re going to compare those qualities in order to settle the 5.56×45 vs 7.62×39 debate – if it can be settled at all.

Most articles like these begin with long-winded histories of the two rounds they’re comparing. We know there are a thousand other places where you can read up on Remington or the Technical Council of the People’s Commissariat for Armaments, so we’re going to spare you a lecture. Let’s jump right into things by taking a look at these two cartridges’ dimensions side by side.

Cartridge Dimensions

7.62x39 vs 5.56 ammo cartridges side by side

 5.56x457.62x39
Case typeRimless, bottleneckRimless, bottleneck
Bullet diameter0.224 in0.309-0.311 in
Neck diameter0.253 in0.339 in
Shoulder diameter0.354 in0.396 in
Base diameter0.377 in0.447 in
Rim diameter0.378 in0.447 in
Rim thickness0.045 in0.059 in
Case length1.760 in1.524 in
Overall length2.260 in2.205 in
Case capacity28.5 gr H2O35.6 gr H2O
Maximum pressure62,366 psi45,010 psi

The obvious difference between the 5.56 and the 7.62 is their bullet diameters. The former is a .22 caliber round, while the latter is a .30 cal. This has big implications for their bullet weights. The 5.56 typically has a 55 grain bullet, although bullets weighing 40, 62, and 77 grains are not uncommon. Its greater diameter means the 7.62 bullet can weigh substantially more – usually 123 grains or very close to it.

Next consider the two rounds’ case capacities – not terribly different from one another, so they can store similar propellant charges. And considering that the 5.56 is loaded to a higher pressure, it only follows that its lighter bullet should deliver a greater muzzle velocity. That’s just physics, folks.

Ballistics Comparison

7.62×39 vs 5.56: Muzzle Velocity

Shooting an AR-15 rifle at the range

 5.56 - Federal American Eagle 55gr FMJBT7.62x39 Federal American Eagle 124gr FMJ
Muzzle velocity (fps)31652350
Velocity @ 50 yds29662213
Velocity @ 100 yds27772081
Velocity @ 150 yds25961953
Velocity @ 200 yds24211831
Velocity @ 250 yds22531714
Velocity @ 300 yds20921603
Velocity @ 350 yds19381499
Velocity @ 400 yds17911402
Velocity @ 450 yds16531312
Velocity @ 500 yds15231233
5.56 - Sellier & Bellot 55gr FMJBT7.62x39 Sellier & Bellot 124gr FMJ
Muzzle velocity (fps)33012421
Velocity @ 50 yds31032274
Velocity @ 100 yds29142132
Velocity @ 150 yds27331995
Velocity @ 200 yds25601864
Velocity @ 250 yds23931738
Velocity @ 300 yds22321619
Velocity @ 350 yds20771508
Velocity @ 400 yds19291404
Velocity @ 450 yds17871310
Velocity @ 500 yds16531227

The 5.56 is a speed demon, often loaded to muzzle velocities in excess of 3,200 fps. The 7.62 is no slouch in terms of velocity either, although its bullet typically exits the muzzle at a rate 20 to 25 percent slower than the 5.56.

The 7.62 rounds we compared all have higher ballistic coefficients than the 5.56 ones, meaning they are able to retain relatively more of their initial velocity as they hurtle downrange. But that’s just not enough to make the 7.62’s trajectory nearly as flat as the 5.56. The 5.56’s lighter, faster bullet gives gravity far less time to pull it down to earth, so it’s bound to evince less drop than its competition.

Trajectory

 5.56x45 Federal American Eagle 55gr FMJBT7.62x39 Federal American Eagle 124gr FMJ
G1 ballistic coefficient0.250.303
G7 ballistic coefficient0.1260.163
Elevation @ 50 yds0.040.86
Elevation @ 100 yds0.581.44
Elevation @ 150 yds00
Elevation @ 200 yds-1.88-3.71
Elevation @ 250 yds-5.24-10.03
Elevation @ 300 yds-10.32-19.3
Elevation @ 350 yds-17.39-31.96
Elevation @ 400 yds-26.78-48.5
Elevation @ 450 yds-38.88-69.47
Elevation @ 500 yds-54.17-95.48
5.56x45 Sellier & Bellot 55gr FMJBT7.62x39 Sellier & Bellot 124gr FMJ
G1 ballistic coefficient0.2590.286
G7 ballistic coefficient0.1270.143
Elevation @ 50 yds-0.050.77
Elevation @ 100 yds0.491.34
Elevation @ 150 yds00
Elevation @ 200 yds-1.65-3.53
Elevation @ 250 yds-4.63-9.57
Elevation @ 300 yds-9.13-18.49
Elevation @ 350 yds-15.38-30.73
Elevation @ 400 yds-23.65-46.8
Elevation @ 450 yds-34.26-67.28
Elevation @ 500 yds-47.59-92.82

The 5.56’s flatter trajectory makes it easier to aim over longer ranges. You’re certain to have better success with the 5.56 for long-distance shooting, especially given the 7.62’s tendency to begin dropping off steeply past the 200 yard mark. But both the 5.56 and 7.62 are plenty accurate at ranges within 100 yards, a distance which most shooters would stay within at the rifle range anyway. Neither one is a sniper round!

Energy

 5.56x45 Federal American Eagle 55gr FMJBT7.62x39 Federal American Eagle 124gr FMJ
Muzzle energy (ft lbs)12241521
Energy @ 50 yds10751349
Energy @ 100 yds9421192
Energy @ 150 yds8231051
Energy @ 200 yds716923
Energy @ 250 yds620809
Energy @ 300 yds535708
Energy @ 350 yds459619
Energy @ 400 yds392541
Energy @ 450 yds334474
Energy @ 500 yds283419
5.56x45 Sellier & Bellot 55gr FMJBT7.62x39 Sellier & Bellot 124gr FMJ
Muzzle energy (ft lbs)13311614
Energy @ 50 yds11761423
Energy @ 100 yds10371251
Energy @ 150 yds9131096
Energy @ 200 yds800956
Energy @ 250 yds699832
Energy @ 300 yds608722
Energy @ 350 yds527626
Energy @ 400 yds454543
Energy @ 450 yds390473
Energy @ 500 yds334414

The 5.56 may have its competition beat in terms of muzzle velocity, yet the 7.62’s bullet compensates for that by weighing about 2 to 2.5 times more. This means it boasts superior energy at all ranges.

Selecting a round for self-defense? Then you don’t really have to worry about which one is more powerful. Either the 7.62 or 5.56 will overwhelm a human-sized target at close range, so the 7.62’s 20 to 25 percent greater muzzle energy doesn’t necessarily mean it will more effectively neutralize a threat. Its wider bullet will carve out a bigger wound channel, however, so its terminal effect does tend to prove a bit more harmful. Icing on the cake, so to speak.

For deer hunting the more powerful 7.62 tops the 5.56. The consensus is that 1,000 ft lbs is the minimum required energy for ethical deer hunting. A 5.56 often fails to transfer that much energy at 100 yards, while the 7.62 can easily extend a hunter’s reach past 150 yards. But it’s important to keep in mind that both rounds were developed for shooting enemies of their respective states of origin, not hunting.

Recoil of 7.62×39 vs 5.56

Shooting 7.62x39 in an AK-47

Recoil is important, friends. We admit it’s thrilling to fire a weapon that kicks like a mule on bath salts, but you wouldn’t want to put up with that kind of abuse all day long. What’s more, heavy recoil complicates self-defense. The more recoil a rifle generates, the more each shot will throw off your carefully lined up aim.

At the end of the day, the amount of recoil you actually perceive is subjective. We can’t quantify what you actually feel. What we can do is objectively measure a cartridge’s recoil energy by considering four factors: bullet weight, propellant weight, muzzle velocity and rifle weight.

Let’s do a real apples-to-apples comparison of the above rounds’ recoil energy. For the sake of this exercise lets assume all six rounds have 24 grains of propellant. We’re firing the 5.56 in a 7.75 lb Windham Weaponry Dissipator Hvy. Bbl and the 7.62 in a 7.7 lb AK-47.

 Recoil Energy (ft lbs)
5.56x45 Federal American Eagle 55gr FMJBT3.54
5.56x45 Sellier & Bellot 55gr FMJBT3.72
5.56x45 Nosler SSA 55gr Ballistic Tip2.95
7.62x39 Federal American Eagle 124gr FMJ6.97
7.62x39 Sellier & Bellot 124gr FMJ7.27
7.62x39 Nosler 123gr Ballistic Tip6.97

The 7.62 might have about 75 percent of the 5.56’s muzzle velocity, but its far heavier bullet makes it deliver about twice as much recoil. It’s important to consider that we picked a relatively heavy AR for the purpose of this comparison. Heavier gun equals less recoil, so if we fired the Federal round in a 6.5 lb Ruger AR-556 its recoil energy would be higher at 4.22 ft lbs – but that’s still less kick than the AK.

To be certain, neither round produces an inconvenient amount of recoil. A normal sized shooter could fire an AK all day long and never get tired of it – and many do. But if you demand lower recoil for your own comfort or to make it easier to direct rapid, accurate fire at a threat, then you’d want the 5.56.

Availability & Price

Assuming the ammo market hasn’t gone bazooey in reaction to some impending apocalypse, finding either 7.62×39 ammo or 5.56 is easy as pie. Put on a blindfold, walk into a gun store, and you’re sure to find both types of ammo. (The store clerks will probably think you’re weird if you do that, so put on a blindfold and shop for ammo on our site instead. Be sure to have an explanation ready for your wife when you wind up blindly ordering 38 cases of blank 22 Short ammo.)

The two rounds also cost about the same. But here’s the thing: While AR owners often note extraction issues when they fire steel-cased 5.56, the AK’s forgiving tolerances enable it to run steel-cased 7.62 with practically zero issues. In a nutshell, by preferring 7.62 you get to take full advantage of all that budget-friendly steel-cased Russian ammo, while it is available. It’s not reloadable, it shoots a little dirtier, and its bullets are magnetic, but hey – you can save a lot of dough with an AK!

The Takeaway: 7.62×39 vs 5.56

The 5.56 offers slightly superior accuracy and lighter recoil. The 7.62 delivers greater energy on impact as well as the opportunity to take better advantage of the cost saving power of steel. It’s a close race, but we’ve overlooked the deciding factor in the 5.56×45 vs. 7.62×39 debate: the rifles.

There are several rifles available chambered for 5.56 ammo, and they will all let you fire nearly identical 223 Rem ammo as well. The most popular of these rifles really nearly begs no mention. When you embrace the 5.56 you get to have fun with the AR-15. It’s endlessly customizable, as cheap or expensive as you want it to be, and extremely reliable. Americans haven’t chosen so practical a rifle as their very favorite because they don’t understand guns.

By comparison the AK-47 isn’t remotely customizable. You can affix a bayonet to it or even give it a rather awkward scope mount if you feel like Mikhail Kalashnikov left something out, but other than that an AK is meant to stay the way it is. Alternatively you could get an SKS instead, but that’s by no means a gun modder’s dream rifle either.

Yet the AK has its blessings. You can get a real workhorse for about $500, and you can abuse the absolute heck out of it before it thinks about jamming up on you. And this may sound biased, but the AK is a very handsome rifle. There’s a certain charm to walnut that polymer will never match.

If you’re on the fence, try out an AR-15 and then an AK-47. See which one you like more, and then decide whether you prefer the 5.56 or 7.62 based solely on that.

Don’t like either rifle? Consider learning kung fu.