338 Win Mag Ballistic Data Guide: Velocity Charts, Performance Testing & Load Comparisons

1. What Is .338 Winchester Magnum?

The .338 Winchester Magnum is a belted magnum cartridge that Winchester introduced in 1958. It is based on the .458 Winchester Magnum case shortened and necked down to accept .338-caliber (.338″) bullets. The design goal was to create a cartridge that bridged the gap between the .30-caliber magnums and the heavy African cartridges — something powerful enough for the largest North American game (including brown bear and moose) while remaining practical for elk-sized animals at extended range.

The .338 Win Mag uses a case length of 2.500 inches with an overall cartridge length of 3.340 inches, fitting standard long-action magnum rifles. It operates at a maximum average pressure of 64,000 PSI and pushes bullets from 185 to 300 grains at genuine magnum velocities. Case capacity is approximately 86 grains of water, which is enough to launch a 225-grain bullet at 2,800 fps — delivering energy levels that dwarf the .30-caliber magnums at any range.

The .338 Win Mag has earned a devoted following among serious big game hunters, particularly in Alaska, the northern Rockies, and Scandinavia. It is one of a handful of cartridges that can confidently handle every land animal in North America with proper bullet selection — from whitetail to grizzly bear. Factory rifles are available from virtually every major manufacturer, including Winchester, Remington, Browning, Tikka, Sako, Weatherby, and Kimber.

The takeaway: The .338 Win Mag is the benchmark large-bore hunting cartridge. It delivers massive energy on target with manageable recoil (relative to its power), making it the first choice for hunters who pursue elk, moose, and bears in serious country.

2. Factory Load Ballistic Data — Complete Table

All velocity figures below are from 24-inch test barrels.

The takeaway: The .338 Win Mag delivers 3,735-4,007 ft-lbs of muzzle energy — roughly 35-40% more than the .300 Win Mag. The 230-grain ELD-X stands out for long-range energy retention with its exceptional .603 BC, while the 225-grain Trophy Bonded Bear Claw is the premium penetration choice for dangerous game.

3. Load-by-Load Performance Breakdown

Hornady 185gr Superformance GMX

The fastest .338 Win Mag factory load at 3,080 fps, the all-copper GMX provides the flattest trajectory in the lineup. Copper construction means zero fragmentation and near-100% weight retention, making it suitable for everything from elk to moose despite its lighter weight. The Superformance propellant blend adds 100-200 fps compared to standard powders, maximizing the .338’s performance potential. This is the load for hunters who want .338 Win Mag power with the flattest possible trajectory.

Federal 200gr Nosler AccuBond

The 200-grain AccuBond at 2,950 fps delivers nearly 3,900 ft-lbs of muzzle energy with manageable recoil (by .338 standards). The bonded core provides 60-70% weight retention and consistent expansion across a wide velocity range. This is the versatile choice — fast enough for 400-yard elk shots, heavy enough for close encounters with bears. Many experienced .338 shooters consider the 200-grain weight the ideal balance point for this cartridge.

Federal 210gr Nosler Partition

The 210-grain Partition at 2,830 fps is a classic big-game bullet that has been trusted on the largest North American game for decades. The dual-core design provides controlled expansion in the front half while the rear partition drives through heavy bone and muscle without breaking apart. For Alaska-bound hunters pursuing moose, caribou, and potentially encountering grizzly bears, the Partition in .338 caliber is a time-tested choice that inspires confidence.

Hornady 230gr Precision Hunter ELD-X

The 230-grain ELD-X at 2,800 fps is the long-range powerhouse of the .338 Win Mag lineup. Its .603 BC — the highest of any factory .338 Win Mag load — means it retains velocity and energy dramatically better than lighter, lower-BC bullets past 300 yards. At 500 yards, it still carries approximately 2,625 ft-lbs of energy, which is more than a .308 Winchester produces at the muzzle. The Heat Shield tip and InterLock ring provide reliable controlled expansion from point-blank to extreme range. If you are hunting elk at 400-500 yards, this is the load.

Federal 225gr Trophy Bonded Bear Claw

This is the dangerous game load. The Trophy Bonded Bear Claw is designed specifically for deep, straight-line penetration on the toughest animals — grizzly bears, brown bears, and large moose at any angle. The bonded lead core is surrounded by a heavy copper jacket that controls expansion to approximately 2x original diameter while retaining 90%+ of its original weight. If you are hunting in bear country and need absolute confidence that your bullet will reach vitals regardless of the angle, this is the load. Many Alaska guides recommend the 225-grain TBBC as their preferred .338 Win Mag load for bear defense.

Nosler 250gr Trophy Grade AccuBond

The heaviest factory option at 250 grains and 2,650 fps, this load delivers maximum momentum for the deepest possible penetration. The AccuBond construction provides controlled expansion while maintaining enough structural integrity to punch through heavy bone on large-bodied game. At close range, the 250-grain AccuBond is devastating on moose and large bears. The trade-off is more recoil and a steeper trajectory than lighter loads. This is a specialized load for the toughest hunting scenarios.

The takeaway: The 200-grain AccuBond is the most versatile choice. For long-range elk, the 230-grain ELD-X is unmatched. For dangerous game defense, the 225-grain Trophy Bonded Bear Claw is the industry standard.

4. Bullet Drop Charts — 100 to 500 Yards

All drop figures based on a 200-yard zero from a 24-inch barrel at sea level.

The takeaway: Despite its heavy bullets, the .338 Win Mag shoots flatter than many shooters expect. The 230-grain ELD-X, despite being one of the heaviest loads, has the second-flattest trajectory thanks to its exceptional BC — only 1.2 inches more drop at 500 yards than the much lighter 185-grain GMX.

5. Barrel Length & Velocity Effects

The .338 Win Mag’s generous case capacity means it responds well to barrel length. Most factory hunting rifles ship with 24 or 26-inch barrels.

The .338 Win Mag loses about 30-35 fps per inch below 24 inches. Going to 22 inches costs roughly 70 fps — still leaving you with over 3,700 ft-lbs of muzzle energy, which exceeds most cartridges’ best performance. For mountain hunting where rifle weight matters, a 22-inch .338 Win Mag is still devastatingly effective. For maximum long-range performance, stick with 24-26 inches.

The takeaway: A 24-inch barrel is the sweet spot for most hunters. Going to 22 inches is acceptable for mountain rifles but costs measurable velocity. Avoid barrels shorter than 22 inches — the increased muzzle blast and concussion from unburned powder become significant.

6. .338 Win Mag vs .300 Win Mag — When Bigger Matters

This is the most common comparison for hunters deciding between large-bore and .30-caliber magnum performance.

The .338 Win Mag delivers 15-20% more energy than the .300 Win Mag at all ranges, with significantly wider wound channels (larger diameter bullets create proportionally larger holes). On elk-sized game, the difference is noticeable — the .338 breaks bone more reliably, penetrates deeper, and creates wider wound channels that produce faster kills. On deer, both are overkill.

The .300 Win Mag counters with less recoil (about 33% less), cheaper ammunition, flatter trajectory with lighter bullets, and a wider selection of factory loads. For most hunters who pursue elk as their largest quarry, the .300 Win Mag is the practical choice. The .338 Win Mag becomes the clear winner when moose, brown bears, or other large-bodied animals are on the menu.

The takeaway: If elk is the biggest animal you will regularly hunt, the .300 Win Mag is enough gun. If you hunt moose, brown bear, or frequently take quartering shots on large elk at distance, the .338 Win Mag provides a meaningful margin of safety.

7. .338 Win Mag vs .338 Lapua Magnum

Both fire .338 caliber bullets, but these are fundamentally different cartridges designed for different purposes.

The .338 Lapua Magnum holds approximately 114 grains of water versus the .338 Win Mag’s 86 grains — a 33% capacity advantage that pushes the same 250-grain bullet 200-250 fps faster. With heavy 300-grain match bullets, the .338 Lapua is a genuine 1,500+ yard cartridge used by military snipers worldwide. The .338 Win Mag is a hunting cartridge that can reach 800-1,000 yards with appropriate loads.

The trade-offs: the .338 Lapua requires a significantly larger rifle platform (magnum-length action with wider receiver), produces roughly 50% more recoil, costs $4-8 per round for factory ammo, and weighs substantially more in a complete rifle package. It is a purpose-built long-range/military cartridge that happens to hunt well, not a hunting cartridge.

The takeaway: For hunting inside 600 yards, the .338 Win Mag does everything the Lapua does with less weight, less recoil, and less cost. The .338 Lapua only makes sense if you regularly shoot past 800 yards or need military-grade long-range capability.

8. Hunting Performance — The Ultimate Big Game Cartridge

The .338 Win Mag excels in situations where you need absolute confidence that your bullet will reach vitals on heavy game. On an elk, the .338 breaks shoulders reliably on quartering shots that would challenge a .30-caliber magnum. On moose, the heavier .338 bullets maintain straight-line penetration through dense muscle and heavy bone. On bears, the combination of energy and bullet weight provides the stopping power needed when the stakes are highest.

The cartridge’s only real limitation as a hunting round is its excessive power on deer-sized game and smaller. A 225-grain .338 bullet traveling at 2,800 fps on a 150-pound whitetail is genuine overkill that can destroy substantial amounts of meat. If deer is your primary game, use a smaller cartridge.

The takeaway: The .338 Win Mag is the definitive North American big game cartridge. It handles elk to 600+ yards, moose to 500+, and provides genuine confidence on bears. Use it for animals that deserve respect — not on deer when a .270 would do the job.

9. Recoil Reality — Managing the .338

The .338 Win Mag produces approximately 35-38 ft-lbs of free recoil energy in a typical 8.5-pound hunting rifle. That is about 33% more than the .300 Win Mag and roughly double the recoil of a .308 Winchester. It is manageable for experienced shooters but challenging for recoil-sensitive individuals or those who do not practice regularly.

Recoil management strategies that work:

• Muzzle brake: Reduces felt recoil by 40-50%, bringing the .338 down to .270 Winchester levels. Essential for practice sessions and load development. Consider a removable brake — hunt with it off to avoid muzzle blast disturbing game.
• Rifle weight: Going from an 8-pound to a 10-pound rifle reduces felt recoil by roughly 25%. For a dedicated .338 Win Mag, do not chase ultralight weight — a heavier rifle is easier to shoot accurately.
• Suppressor: Offers 20-30% recoil reduction plus hearing protection. The added barrel weight improves recoil characteristics significantly. Increasingly the preferred option for serious .338 Win Mag shooters.
• Shooting fundamentals: A solid cheek weld, firm but not death-grip hold, and proper stance manage recoil better than any accessory. Practice with your .338 regularly — do not be the hunter who sights in once a year and flinches on game.

The takeaway: The .338 Win Mag kicks hard enough to degrade accuracy if you are not prepared. Invest in a muzzle brake or suppressor for practice, maintain your shooting fundamentals, and never try to shoot a .338 Win Mag from a bench without recoil mitigation.

10. Choosing the Right .338 Win Mag Load

The .338 Win Mag enjoys excellent factory ammo support from all major manufacturers. Winchester, Federal, Hornady, Nosler, and several others produce multiple load options. Premium hunting ammunition typically runs $3-5 per round, so practice ammo should be a separate budget line item. Online retailers like Tatted Tacticals typically maintain broader selection than local stores for this caliber.

The takeaway: Match your bullet to your game’s toughness. Light, fast bullets (185-200 grains) for versatility and flat trajectories. Heavy, bonded bullets (225-250 grains) for the largest and most dangerous game.

11. FAQ

Is the .338 Win Mag overkill for elk?

No. While some hunters argue it is more than necessary, the .338 Win Mag is purpose-built for elk-sized game and is one of the most popular elk cartridges in the western states. Its advantages — deeper penetration, wider wound channels, and more forgiving shot angles — are real benefits in the field. Where the .338 becomes overkill is on deer-sized game, where a .270 or .308 does the job with less recoil and meat damage.

How much recoil does the .338 Win Mag produce?

Approximately 35-38 ft-lbs of free recoil energy in a typical 8.5-pound rifle — about 33% more than the .300 Win Mag and roughly double the .308 Winchester. A muzzle brake reduces this by 40-50%, and a suppressor provides 20-30% reduction plus hearing protection. Most experienced shooters can manage .338 Win Mag recoil with proper technique and regular practice.

What is the effective range of the .338 Win Mag?

For elk-class game, the .338 Win Mag is effective to 600+ yards with premium 225-230 grain bullets. For the largest game (moose, brown bear), effective range is 400-500 yards. For target shooting, the .338 remains supersonic to approximately 1,200 yards with high-BC 230+ grain match bullets.

Is the .338 Win Mag good for brown bear?

Yes. The .338 Win Mag is widely considered the minimum adequate cartridge for brown and grizzly bears by many experienced Alaska guides. With 225-250 grain premium bonded bullets (Trophy Bonded Bear Claw, AccuBond, or Partition), it provides the energy and penetration needed for reliable kills on the largest bears. Many Alaska guides carry .338 Win Mag rifles as their personal bear rifles.

How does .338 Win Mag compare to .375 H&H?

The .375 H&H hits harder with heavier bullets (270-300 grains) and is the minimum legal caliber for dangerous game in many African countries. The .338 Win Mag is lighter, faster with equivalent-weight bullets, and shoots flatter. For North American game including brown bears, the .338 Win Mag is adequate. For African dangerous game (cape buffalo, elephant), you need the .375 H&H or larger.

What barrel twist rate does the .338 Win Mag need?

A 1:10 twist is the standard for .338 Win Mag and stabilizes bullets from 185 to 250 grains. This twist rate works for all common factory loads. For the heaviest 285-300 grain match bullets, a 1:9.5 or faster twist may be needed, but these bullets are primarily used in the .338 Lapua, not the .338 Win Mag.

Ready to stock up on .338 Win Mag ammunition? Browse our full selection of .338 Win Mag ammo at Tatted Tacticals — from premium elk loads to dangerous game ammunition.