Published: 2025 | Last updated: March 2026
The 5.56 NATO and 7.62x39mm are two of the most widely used intermediate cartridges on earth. Between them, they have equipped more rifles, been fired in more conflicts, and accounted for more deer, hogs, and coyotes in North America than any other two cartridges of the modern era. Yet their ballistic personalities could not be further apart.
The 5.56 NATO is small-bore, high-pressure, and fast – a precision tool that trades bullet weight for velocity and relies on that velocity for terminal effect. The 7.62×39 is larger-bore, lower-pressure, and deliberate – a blunt instrument that trades speed for mass and delivers its authority through frontal diameter and momentum at close to moderate range. Choosing between them is not about deciding which is better in the abstract. It is about deciding which set of trade-offs fits the terrain you hunt, the game you pursue, and the distances you realistically shoot.
This guide covers every dimension of that comparison: technical architecture, ballistics with concrete numbers, terminal performance, platform considerations, handloading, and a verdict that is honest about what each cartridge does well and where it runs out of capability.
Technical Architecture
How the 5.56 NATO is Built
The 5.56 NATO fires a .224-inch diameter bullet – a small bore by hunting standards – at pressures of 55,000-62,000 PSI depending on specification (.223 Remington vs military 5.56 NATO). The case is short and efficient, holding approximately 28-31 grains of water. Standard bullet weights run from 55 to 77 grains, with 55-grain and 62-grain being the most common in factory ammunition.
The cartridge achieves its velocity advantage through pressure. By running at higher pressure than most rifle cartridges of equivalent case volume, the 5.56 pushes 55-grain bullets to approximately 3,100-3,250 fps from standard 16-inch AR-15 barrels – a velocity that produces explosive terminal effect on small animals and, with appropriate bullet design, adequate performance on deer-sized game.
Everything in the 5.56 NATO’s design prioritizes velocity. The small bore, the light bullets, the high pressure – all of it exists to move projectiles faster than a physically larger cartridge could from the same case volume. The trade-off is that terminal performance depends on that velocity remaining above approximately 2,200 fps at impact. Below that threshold, many 5.56 projectiles do not reliably expand.
How the 7.62x39mm is Built
The 7.62x39mm fires a .310-.312-inch diameter bullet at 45,000 PSI – a moderate-pressure, larger-bore design built around a completely different set of priorities. Standard bullet weight is 123-125 grains. Muzzle velocity from a 16-inch AK-pattern carbine is approximately 2,300-2,350 fps.
The Soviet M43 cartridge, developed in the early 1940s and first used in the SKS before becoming synonymous with the AK-47, was designed to balance adequate range with compact logistics. The 7.62×39 is not trying to be flat-shooting or precision-accurate at extended range. It is designed to be reliable in any conditions, to cycle smoothly through a gas-operated action under field stress, and to produce authoritative close-range terminal effects through bullet mass and bore diameter rather than velocity.
The result is a cartridge that produces more muzzle energy than its moderate velocity suggests – the 123-grain bullet’s mass more than compensates – and that retains terminal effectiveness at the moderate distances its trajectory actually supports.
The Engineering Trade-Off in Plain Terms
The 5.56 NATO bets on velocity. The 7.62×39 bets on mass. Both bets pay off within the cartridge’s intended operating range and fail outside it. Understanding where those ranges end is the entire comparison.
Technical Comparison Table
| Characteristic | 5.56 NATO / 223 Rem | 7.62x39mm |
|---|---|---|
| Bullet Diameter (inches) | 0.224 | 0.310-0.312 |
| Typical Bullet Weight (grains) | 55-77 | 123-125 |
| Muzzle Velocity (fps, 16″ barrel) | 3,100-3,250 (55 gr) | 2,300-2,380 (123 gr) |
| Muzzle Energy (ft-lbs) | ~1,180-1,280 | ~1,445-1,550 |
| SAAMI Max Pressure (PSI) | 55,000 (.223 Rem) | 45,000 |
| Effective Deer Range | ~250-300 yards | ~200-250 yards |
| Free Recoil (7-lb rifle, ft-lbs) | ~5 | ~9 |
| Case Length (inches) | 1.760 | 1.524 |
| Cartridge Overall Length (inches) | 2.260 | 2.205 |
Ballistics in the Field
Velocity and Trajectory
The 5.56 NATO’s velocity advantage produces a meaningfully flatter trajectory. The numbers below use a 55-grain load at 3,200 fps for the 5.56 and a 123-grain load at 2,350 fps for the 7.62×39, both zeroed at 100 yards:
| Distance (yards) | 5.56 NATO, 55 gr | 7.62×39, 123 gr |
|---|---|---|
| Velocity / Energy / Drop | Velocity / Energy / Drop | |
| 0 | 3,200 fps / 1,250 ft-lbs / – | 2,350 fps / 1,508 ft-lbs / – |
| 100 | 2,815 fps / 968 ft-lbs / 0″ | 2,090 fps / 1,193 ft-lbs / 0″ |
| 200 | 2,455 fps / 736 ft-lbs / -7.0″ | 1,850 fps / 936 ft-lbs / -10.5″ |
| 300 | 2,118 fps / 548 ft-lbs / -22.0″ | 1,628 fps / 724 ft-lbs / -32.0″ |
| 400 | 1,805 fps / 398 ft-lbs / -47.5″ | 1,429 fps / 558 ft-lbs / -67.5″ |
Standard conditions: 59°F, sea level, 1.5-inch sight height, zeroed at 100 yards.
For complete ballistics data, see the 223 Remington ballistics page and 7.62x39mm ballistics page.
Two things stand out from this table. First, the 5.56 NATO’s trajectory advantage grows with distance – 3.5 inches at 200, 10 inches at 300, 20 inches at 400. In terrain where shots are uncertain and range estimation is imprecise, that difference matters. Second, the 7.62×39 carries more energy at every distance. The heavier, slower bullet retains energy more efficiently than the fast, light 5.56 bullet, which bleeds velocity quickly in the lower-density air beyond midrange. By 400 yards the 7.62×39 carries 558 ft-lbs versus the 5.56’s 398 ft-lbs – a 40% energy advantage from a cartridge that started nearly 30% slower.
Wind Drift
The 5.56 NATO’s high velocity does not overcome its light bullet’s poor ballistic coefficient in wind. The 55-grain 5.56 bullet drifts approximately 8-9 inches at 300 yards in a 10 mph crosswind. The 123-grain 7.62×39 bullet drifts approximately 12-14 inches at 300 yards in the same wind. The 5.56 has a modest wind drift advantage, but at 300 yards the trajectory difference is more practically significant than the wind drift difference for most hunters.
The Velocity Threshold for Terminal Performance
This is the most important ballistic fact for hunters considering either cartridge. The 5.56 NATO’s terminal performance depends on the bullet exceeding approximately 2,200 fps at impact. Below that velocity, many 5.56 bullets fail to reliably expand or fragment – the mechanism that makes them effective on game. From a 16-inch AR-15 barrel running a standard 55-grain factory load, that threshold is reached at approximately 300-325 yards.
From a 20-inch precision bolt rifle, the 5.56 maintains terminal effectiveness to approximately 375-400 yards. From a 14.5-inch carbine or shorter, the threshold may occur as close as 250 yards.
The 7.62×39 does not have this problem in the same way – its terminal performance at hunting distances comes primarily from frontal diameter and momentum, which degrade more gradually than velocity-dependent fragmentation. A 7.62×39 123-grain soft point at 1,600 fps still expands reliably. The cost is that by 300 yards, the 7.62×39 is running at that velocity, and its trajectory has already committed the shooter to a 32-inch holdover.
Platform Considerations
5.56 NATO Platforms
The AR-15 dominates the 5.56 NATO platform landscape. The AR-15 is light – typically 6.5-7.5 pounds – ergonomic, fast-handling, and carries 20-30 round magazines that are rarely relevant for hunting but contribute to the platform’s versatility for predator control and varmint shooting. Barrel length options run from 10.5-inch pistols to 24-inch precision configurations; the practical hunting sweet spot is 16-20 inches.
Bolt-action options in .223 Remington include the Ruger American, Howa Mini, and Tikka T3x – lighter, more accurate platforms that sacrifice the semi-automatic follow-up capability but deliver better precision from a bench. For dedicated varmint hunters, a quality bolt-action .223 Remington often outperforms an AR-15 in pure accuracy at extended ranges.
7.62x39mm Platforms
The AK-pattern rifle (AKM, AK-47, and their variants) is the 7.62×39’s natural home. AK-pattern rifles are reliable under adverse conditions – the gas-piston system and loose tolerances that define AK function were specifically engineered for reliability in mud, sand, and cold. They are typically 7-8 pounds, feed reliably from curved 30-round magazines, and tolerate conditions that would choke a tighter-tolerance AR-15.
Bolt-action options include the CZ 527 Carbine (a classic, highly accurate option), Ruger American, and Howa Mini. The CZ 527 in 7.62×39 is particularly respected among hunters who want the cartridge’s terminal characteristics with bolt-action precision.
Critical note for handloaders: 7.62x39mm rifles vary in bore diameter. Most modern commercial bolt-action and some semi-automatic rifles use a .308-inch groove diameter. Many surplus military-specification AK barrels use .311-.312-inch groove diameter. Loading .308-inch bullets in a .311-inch bore produces gas leakage past the undersized bullet and degrades accuracy. Loading .311-inch bullets in a .308-inch bore raises pressure. Measure or have a gunsmith measure the groove diameter of your specific 7.62×39 rifle before selecting handload bullets.
Terminal Performance and Hunting Applications
5.56 NATO for Hunting
The 5.56 NATO performs well for varmints and predators at any practical range. For deer-sized game, it works reliably inside its velocity window with the right bullet.
Appropriate 5.56 hunting bullets include:
- Hornady ELD-X 55-grain: reliable expansion at lower velocities; good choice for range uncertainty
- Barnes TSX 55-grain: monolithic copper; reliable expansion from 1,800 fps and above; lead-free
- Nosler Ballistic Tip 55-grain: reliable varmint and deer expansion at velocity
- Sierra GameKing 55-grain SPBT: traditional soft point; adequate for deer at moderate ranges
Inappropriate 5.56 hunting loads: Military FMJ (M193, M855, green-tip) is not designed to expand on game and is not appropriate for ethical deer hunting. It meets the legal minimum (centerfire rifle) but does not meet the ethical standard.
Practical 5.56 deer hunting range: With a 20-inch barrel and premium expanding bullet, 300 yards is a reasonable ethical limit. With a 16-inch barrel, 250 yards is more honest. Know your specific rifle, chronograph your chosen load, and establish your velocity floor before hunting.
7.62x39mm for Hunting
The 7.62×39 excels for hogs, deer, and black bear at timber and brush ranges. Its 123-grain soft point or hollow point produces reliable expansion from factory velocities through extended range because the expansion mechanism (soft point deformation) does not depend on fragmenting above a velocity threshold.
Appropriate 7.62×39 hunting bullets include:
- Hornady SST or FTX 123-grain: polymer tip; excellent controlled expansion
- Soft point hunting loads: Federal Power-Shok, Remington Core-Lokt in 7.62×39 – reliable, affordable deer loads
- Barnes TTSX 110-grain: lead-free; deep penetration for hogs and bears
Practical 7.62×39 deer hunting range: 200 yards is the practical limit where trajectory management remains straightforward and energy is adequate. At 250 yards, the 7.62×39 retains approximately 800 ft-lbs and drops roughly 20 inches from a 150-yard zero – manageable, but requiring deliberate holdover calculation. Beyond 300 yards, both the energy margin and the trajectory become demanding.
For the 7.62×39 vs 300 Blackout comparison in suppressed and short-barrel contexts, see our 7.62×39 vs 300 AAC Blackout comparison.
Reloading
5.56 NATO / 223 Remington
The 223 Remington is one of the best-supported handloading cartridges available. Brass from Hornady, Federal, Winchester, and Lapua is widely available at reasonable prices. Bullet selection covers 40-grain varmint through 77-grain match, in every construction type. Component costs are among the lowest of any centerfire rifle cartridge.
Powders for 223 Remington / 5.56 NATO:
| Powder | Bullet Weights (grains) | Charge Range (grains) | Best For |
|---|---|---|---|
| Hodgdon Varget | 60-77 | 23.5-26.5 | Accuracy; temp stable; heavy bullets |
| IMR 4064 | 55-69 | 24.0-26.5 | Classic choice; versatile |
| IMR 4895 | 50-69 | 23.5-26.5 | All-around; proven |
| Alliant Reloder 15 | 55-69 | 24.0-27.0 | Temperature stable; hunting loads |
| Hodgdon H4350 | 69-77 | 24.0-27.0 | Slowest burn; 69-77 gr match |
Note: AR-15 requires full-length sizing. Crimped military primer pockets must be swaged or reamed before the first reload.
7.62x39mm
The 7.62×39 is handloadable but requires attention to a few constraints the .223 Remington does not have.
Brass: Steel-cased military surplus is not reloadable with standard equipment. Commercial brass from Starline (the primary source) or Hornady is required. Starline 7.62×39 brass is excellent quality and widely available.
Bullet diameter: Confirmed above – measure your bore before ordering bullets. Starline brass is loaded to standard .308-inch diameter for standard commercial barrels. If your rifle has a .311-inch bore, you need .311-inch bullets.
Powders for 7.62x39mm:
| Powder | Bullet Weights (grains) | Charge Range (grains) | Best For |
|---|---|---|---|
| Hodgdon H4895 | 123-125 | 25.5-28.5 | Accuracy; all-around |
| IMR 4064 | 123-125 | 25.0-27.5 | Traditional choice; hunting |
| Hodgdon Varget | 123-125 | 25.0-28.0 | Temperature stable; accuracy |
| Alliant Reloder 15 | 123-125 | 25.5-28.5 | General purpose; temp stable |
| IMR 4895 | 110-125 | 24.5-28.0 | Versatile; lighter bullets |
Maximum pressure for 7.62×39 is 45,000 PSI SAAMI. Begin at minimum and work up carefully. Verify against current Hodgdon or Lyman 7.62×39-specific data before loading.
Strengths and Limitations Summary
5.56 NATO
Strengths:
- Flat trajectory inside 300 yards – the flattest of any common hunting cartridge in this bore class
- Lightest recoil of any centerfire deer cartridge – enables extended practice sessions and fast shot-calling
- Widest factory ammunition selection and component variety of any rifle cartridge
- Excellent varmint and predator performance at any practical range
- AR-15 platform provides semi-automatic follow-up capability for predator control
Limitations:
- Terminal performance depends on maintaining velocity above ~2,200 fps – range-limited by the specific barrel length and load combination
- Energy at extended range falls off faster than the 7.62×39 despite starting higher
- Not an appropriate hog or bear cartridge; marginal for deer at ranges where the heavier bullet matters
7.62x39mm
Strengths:
- More energy at all distances despite lower velocity – the heavier bullet retains it better
- Terminal performance does not depend on a velocity threshold – reliable expansion from factory velocities throughout the practical range
- Well-suited for hogs, deer, and black bear in timber where shots are 200 yards and under
- AK-platform reliability in adverse field conditions is legendary
Limitations:
- Trajectory becomes demanding beyond 200-250 yards – drop and wind drift limit practical hunting range
- Less flat at short range than the 5.56, requiring more precise holdover at longer timber shots
- 7.62×39 handloading is more constrained than .223 Remington due to bore diameter variation and brass availability
The Verdict
The choice between these cartridges is fundamentally a terrain and distance question, not a performance question. Neither cartridge is deficient in its natural role; both are deficient outside it.
Choose 5.56 NATO if: You hunt in open or mixed terrain where shots may extend beyond 200 yards; you pursue varmints and predators as primary or secondary targets; you want the lightest possible recoil for extended practice; or you want the flattest trajectory available in a semi-automatic platform.
Choose 7.62x39mm if: You hunt primarily in timber or thick cover where shots are under 200 yards; you want heavier bullet impact on deer, hogs, or black bear without depending on high velocity to achieve it; you want the reliability of an AK-pattern platform in harsh field conditions; or your game includes animals heavy enough that the 5.56’s light-bullet terminal performance feels marginal.
The 5.56 NATO rewards the hunter who knows their range and uses appropriate bullets. The 7.62×39 rewards the hunter who hunts close and wants simple, heavy terminal authority. Neither forgives being used outside its design envelope.
For caliber selection guidance across a wider range of hunting scenarios, see our how to choose the right caliber for hunting guide.
Editorial note: This article was originally published in 2025 and substantially revised in March 2026. The update added concrete ballistics tables with velocity, energy, and drop figures at each distance for both cartridges; added the velocity threshold explanation for 5.56 terminal performance; added the 7.62×39 bore diameter warning for handloaders with specific guidance; expanded the platform section with bolt-action options for both calibers; added complete powder tables with charge ranges; and substantially expanded the hunting applications section with specific bullet recommendations and honest range limits.
