Published: January 2026 | Last updated: April 2026
Disclaimer: All load data referenced in this article is drawn from published reloading manuals. The 338 Winchester Magnum operates at 64,000 PSI with large, slow-burning powder charges. Always begin 10% below published maximum charges and work up carefully. Large rifle magnum primers are required for most loads. Never exceed published maximums.
The 338 Winchester Magnum was introduced in 1958 as Winchester’s first .338-caliber belted magnum, chambered in the Winchester Model 70. The design brief was straightforward: produce a cartridge capable of ethical kills on elk, moose, and North American bears – including brown and grizzly bears – at hunting distances from brush-country 50-yard encounters to open-country 400-yard shots. The 338 Winchester Magnum accomplished this with a 225-grain bullet at 2,800 FPS and a 250-grain bullet at 2,660 FPS, delivering the combination of heavy bullet weight, adequate velocity, and controlled expansion that large game demands.
Sixty-five years after its introduction, the 338 Winchester Magnum is the dominant .338-caliber cartridge for North American hunting. Factory ammunition is available from every major manufacturer. Rifles are chambered by Winchester, Remington, Savage, Ruger, and most other production manufacturers. The belted case headspaces consistently, the powder selection is well-documented, and the .338-inch bullet library from 180 to 300 grains covers every application from deer to dangerous game. No other .338-caliber cartridge approaches the 338 Winchester Magnum‘s combination of performance, availability, and rifle selection for standard hunting use.
Technical Characteristics
| Characteristic | Value |
|---|---|
| Bullet Diameter | 0.338 inches |
| Case Length | 2.500 inches |
| Overall Cartridge Length | 3.340 inches (max) |
| Case Capacity | ~86-88 grains H2O |
| Case Type | Belted magnum |
| Belt Diameter | 0.532 inches |
| Max Avg Pressure (SAAMI) | 64,000 PSI |
| Typical Bullet Weight | 180-300 gr |
| Muzzle Velocity (200 gr) | ~2,950 FPS |
| Muzzle Velocity (225 gr) | ~2,800 FPS |
| Muzzle Velocity (250 gr) | ~2,660 FPS |
| Muzzle Velocity (300 gr) | ~2,450 FPS |
| Muzzle Energy (225 gr) | ~3,916 ft-lbs |
The belted magnum case headspaces on the belt rather than the shoulder. This means the shoulder position does not control headspace, which affects how the case is sized for reloading. Full-length size after every firing for reliable chambering. The shoulder will set back slightly over multiple firings as the belt continues to control headspace – this is normal for belted designs. Check case head wall thickness ahead of the belt after 5-6 firings to monitor for thinning.
Recoil
The 338 Winchester Magnum’s recoil depends significantly on rifle weight and stock design. In a standard 9-pound hunting rifle, it is approximately 28-32 ft-lbs – noticeably heavier than the 300 Winchester Magnum and the most recoil that most hunters who shoot from field positions manage comfortably over a season.
| Cartridge | Recoil (ft-lbs) | Rifle Weight (lbs) | Notes |
|---|---|---|---|
| 300 Winchester Magnum | 22-25 | 9.0 | Standard .30-caliber magnum reference |
| 338 Federal | 22-25 | 8.0 | Short-action; less recoil |
| 338 Winchester Magnum | 28-32 | 9.0 | Full magnum; noticeable; manageable |
| 338 Lapua Magnum | 35-40 | 12.0 | Significantly heavier; purpose-built rifles |
| 338 Weatherby Magnum | 30-35 | 9.0 | More velocity; more recoil |
A quality recoil pad is important equipment for a 338 Winchester Magnum. Extended bench sessions for load development benefit from a mechanical rest. In the field, the adrenaline of a hunting situation suppresses felt recoil and most hunters report the 338 Winchester Magnum as manageable for the shooting they actually do.
Twist Rate
| Twist Rate | Optimal Bullet Weight | Barrel Length | Notes |
|---|---|---|---|
| 1:10 | 225-300 gr | 24-26 in | Production standard; handles all practical weights |
| 1:11 | 200-225 gr | 22-24 in | Adequate for main hunting weights |
| 1:12 | 180-200 gr | 20-24 in | Lighter bullets; limits heaviest options |
Most production 338 Winchester Magnum rifles use 1:10 twist, which handles the full practical bullet weight range from 200 to 300 grains. A 24-inch barrel is the standard for factory data; a 22-inch mountain rifle loses approximately 60-80 FPS.
Ballistics and Field Performance
Trajectory
| Distance (yards) | Velocity (FPS) | Energy (ft-lbs) | Drop (inches) |
|---|---|---|---|
| Muzzle | 2,800 | 3,916 | -1.5 |
| 50 | 2,712 | 3,673 | +0.5 |
| 100 | 2,625 | 3,443 | +1.5 |
| 150 | 2,540 | 3,225 | +1.2 |
| 200 | 2,457 | 3,018 | 0.0 |
| 300 | 2,296 | 2,637 | -6.5 |
| 400 | 2,140 | 2,291 | -19.5 |
| 500 | 1,990 | 1,979 | -40.8 |
| 600 | 1,847 | 1,704 | -71.5 |
225-grain hunting bullet, BC 0.472, 2,800 FPS muzzle velocity. 59°F, sea level, 1.5-inch sight height, 200-yard zero.
At 500 yards the 338 Winchester Magnum with a 225-grain bullet delivers 1,979 ft-lbs – well above the threshold for elk and moose. At 600 yards it is at 1,704 ft-lbs, still adequate for large game with quality bonded bullets and precise shot placement. The cartridge’s practical hunting range on elk and moose is 500-550 yards; on bears where shots are typically closer, 400 yards is a practical limit where shot placement needs to be precise on a vital-area shot.
Caliber Comparison
| Cartridge | Bullet (gr) | MV (FPS) | Energy @400 yds | Notes |
|---|---|---|---|---|
| 300 Winchester Magnum | 180 | 2,960 | ~2,054 ft-lbs | .30-cal; lighter bullet; flatter |
| 338 Winchester Magnum | 225 | 2,800 | ~2,291 ft-lbs | The standard big-game .338 |
| 338 Federal | 200 | 2,630 | ~1,299 ft-lbs | Short-action; less range |
| 338 Lapua Magnum | 250 | 2,950 | ~3,050 ft-lbs | ELR specialist; much more everything |
The 338 Winchester Magnum delivers 237 more ft-lbs at 400 yards than the 300 Winchester Magnum in the comparison above, and does it through a heavier, wider bullet with higher sectional density. On elk and moose where shoulder penetration matters, the .338-inch bullet’s advantage over the .308-inch bullet is real at any velocity.
Reloading the 338 Winchester Magnum
Primers
Large rifle magnum primers are the standard. Standard large rifle primers can work with lighter charges and faster powders, but magnum primers are appropriate for the primary load range.
| Primer | Type | Application |
|---|---|---|
| CCI 250 | Large Rifle Magnum | Standard choice; reliable; widely available |
| Federal 215 | Large Rifle Magnum | Hottest standard primer; cold conditions; slow powders |
| Federal GM215M | Large Rifle Magnum Match | Precision loads; lowest standard deviation |
| Remington 9-1/2M | Large Rifle Magnum | Dependable; good for hunting loads |
| Winchester WLRM | Large Rifle Magnum | Consistent; works well with slower powders |
| Winchester WLR | Large Rifle | Only for lighter charges with faster powders |
Cases
Winchester, Norma, Nosler, and Lapua produce 338 Winchester Magnum brass. All are Boxer-primed and compatible with standard reloading equipment.
| Brand | Notes |
|---|---|
| Winchester | Primary manufacturer; most available; consistent; standard choice |
| Norma | Premium quality; excellent consistency; good for precision work |
| Nosler | Good quality; consistent; slightly less available |
| Lapua | Premium quality; best case life; produces 338 Win Mag periodically |
| Remington | Good quality; widely available |
Belted case sizing procedure: full-length size after every firing. The belt headspaces the case, not the shoulder. Standard shoulder bump sizing techniques do not apply here – the belt maintains consistent headspace regardless of shoulder position. This means more case stretching than a rimless design and more careful monitoring of case head condition.
Trim to 2.490 inches after each firing. Anneal every 3-4 firings. At 64,000 PSI with a large case, brass works quickly and regular annealing is important for consistent neck tension. Properly maintained brass delivers 5-7 reloadings at standard hunting charge weights.
Bullets
The 338 Winchester Magnum has the broadest bullet selection of any .338-caliber cartridge – from 180-grain deer bullets to 300-grain dangerous game solids. The practical hunting range centers on 200-250 grains.
| Bullet | Weight | Type | Application | Notes |
|---|---|---|---|---|
| Sierra GameKing | 200 gr | SBT | Deer, elk; lighter option | Flat trajectory; good BC; less recoil in charge |
| Hornady InterLock | 200 gr | SP | Deer, elk; economical | Traditional; proven; widely available |
| Nosler Ballistic Tip | 200 gr | BT | Deer, antelope | Good BC; rapid expansion |
| Nosler AccuBond | 225 gr | Bonded BT | Elk, moose; standard hunting | The benchmark 338 Win Mag hunting bullet |
| Hornady ELD-X | 230 gr | Polymer Tip | Elk at range | High BC; controlled expansion; excellent |
| Sierra GameKing | 225 gr | SBT | Deer, elk; general hunting | Accurate; reliable expansion |
| Nosler Partition | 225 gr | Partition | Elk, moose, bears | Maximum penetration; any-angle reliability |
| Berger VLD Hunting | 230 gr | VLD | Long-range elk hunting | High BC; precision hunting |
| Sierra GameKing | 250 gr | SBT | Moose, large bears | Heavy bullet; deep penetration |
| Nosler Partition | 250 gr | Partition | Moose, brown/grizzly bear | Heavy; maximum penetration |
| Hornady InterLock | 250 gr | SP | Large game; economical | Traditional; proven on large animals |
| Barnes TTSX | 225 gr | Copper HP | Lead-free; tough game | Deep penetration; California legal |
| Nosler Partition | 300 gr | Partition | Brown/grizzly bear defense | Maximum mass and penetration |
The Nosler AccuBond 225-grain is the consensus standard for 338 Winchester Magnum elk hunting – bonded construction, good BC, and designed to perform reliably from close-range 2,800 FPS impacts to 400-yard 2,300 FPS impacts. For brown bear and grizzly bear encounters, the Nosler Partition 250-grain or 300-grain provides the controlled expansion and maximum penetration that dangerous game requires.
Powders
The 338 Winchester Magnum’s 86-88 grain case calls for medium-slow to slow burning powders. Hodgdon H4831SC is the traditional standard; Alliant Reloder 22 and IMR 4831 are the primary alternatives.
| Powder | Bullet Weight | Start Charge | Max Charge | Approx Velocity | Notes |
|---|---|---|---|---|---|
| Hodgdon H4831SC | 200-225 gr | 71.0 gr | 79.0 gr | ~2,870 FPS | Classic choice; most published data; consistent |
| Hodgdon H4831SC | 225-250 gr | 68.0 gr | 76.0 gr | ~2,760 FPS | Good with heavier hunting bullets |
| IMR 4831 | 200-250 gr | 70.0 gr | 78.0 gr | ~2,840 FPS | Classic big-game powder; versatile |
| Alliant Reloder 22 | 200-250 gr | 72.0 gr | 80.0 gr | ~2,850 FPS | Good velocity; consistent; widely used |
| Alliant Reloder 22 | 225-300 gr | 69.0 gr | 77.0 gr | ~2,750 FPS | Good with all hunting bullet weights |
| Hodgdon H4350 | 200-225 gr | 70.0 gr | 78.0 gr | ~2,880 FPS | Temperature stable; good with lighter bullets |
| IMR 4350 | 200-225 gr | 70.0 gr | 78.0 gr | ~2,870 FPS | Classic medium-slow; versatile |
| IMR 7828 SSC | 225-250 gr | 71.0 gr | 79.0 gr | ~2,820 FPS | Good consistency; heavier bullets |
| Vihtavuori N560 | 225-250 gr | 72.0 gr | 80.0 gr | ~2,840 FPS | Premium consistency; good precision loads |
| Alliant Reloder 25 | 250-300 gr | 72.0 gr | 80.0 gr | ~2,720 FPS | Good with heaviest bullets |
| Hodgdon H1000 | 250-300 gr | 73.0 gr | 81.0 gr | ~2,700 FPS | Best with heaviest bullets; consistent SD |
| Hodgdon Retumbo | 250-300 gr | 75.0 gr | 83.0 gr | ~2,720 FPS | Very slow; best case fill for heaviest bullets |
| Ramshot Magnum | 200-225 gr | 70.0 gr | 78.0 gr | ~2,830 FPS | Ball powder; consistent metering |
| Accurate MagPro | 225-250 gr | 71.0 gr | 79.0 gr | ~2,790 FPS | Ball powder; good metering; consistent |
| Norma MRP | 225-250 gr | 71.0 gr | 79.0 gr | ~2,810 FPS | Good consistency; natural pairing with Norma brass |
All charge weights are reference figures. Verify against current published Winchester, Hodgdon, Alliant, or Norma data before loading. Begin 10% below listed maximums. Work up in 0.5-grain increments.
Hodgdon H4831SC is the standard 338 Winchester Magnum powder with decades of published data and reliable results in most barrels. The SC (Short Cut) variant meters better than standard H4831 while producing identical performance. For 200-225 grain hunting bullets, H4831SC is the default starting point.
Alliant Reloder 22 produces competitive velocity with good consistency and works well across the full 200-300 grain bullet range. For hunters who want one powder that handles everything from deer loads with 200-grain bullets to dangerous game loads with 250-grain bullets, Reloder 22 is a practical choice.
Hodgdon H1000 and Hodgdon Retumbo are the choices for the heaviest 250-300 grain bullets where their slower burn rates fill the case more completely and reduce position sensitivity.
Practical Hunting Applications
Elk
This is the 338 Winchester Magnum’s primary North American application and its strongest suit. At 400 yards with a 225-grain Nosler AccuBond at 2,800 FPS, it delivers 2,291 ft-lbs – generous for elk with a controlled-expansion bullet and precise shot placement. The .338-inch bullet’s diameter and sectional density produce the penetration that elk hunters who have tracked shot animals appreciate: a 338 Winchester Magnum hit leaves a blood trail.
Use bonded construction for elk – the Nosler AccuBond 225-grain or Nosler Partition 225-grain. Both handle the full velocity range from close-range impact at 2,800 FPS to extended-range shots arriving below 2,400 FPS without bullet failure.
Moose
The 338 Winchester Magnum with a 250-grain Nosler Partition or Sierra GameKing at 2,660 FPS is among the most capable standard-production hunting cartridges for moose. The combination of bullet weight, velocity, and .338-inch bore diameter produces the deep penetration and wide wound channel that moose hunters require. The cartridge’s history in Alaskan and Canadian moose country is extensive and well-documented.
Brown Bear and Grizzly Bear
The 338 Winchester Magnum is used for brown and grizzly bear hunting and is adequate for the application with appropriate bullet selection. The Nosler Partition 250-grain and 300-grain are the choices for dangerous game where penetration through heavy bone and muscle to the vitals is the priority over BC. Keep shots to broadside or clear quartering-away angles and use heavier bullets than you would for deer or elk.
For bear defense in close-quarters situations, the 250-grain or 300-grain Nosler Partition provides the penetration insurance that a charging bear requires. The 338 Lapua Magnum is more capable at distance, but the 338 Winchester Magnum in a standard hunting rifle is a practical and adequate dangerous game cartridge inside 200 yards.
Conclusion
The 338 Winchester Magnum has earned its status as the dominant .338-caliber hunting cartridge through 65 years of field results on North America’s largest and toughest game. Its combination of adequate velocity, heavy bullet weight, belted magnum reliability, and broad commercial availability makes it the most practical choice in its power class for any hunter who wants a .338-caliber cartridge for elk, moose, or bears.
The 338 Lapua Magnum exceeds it at distance and the 338 Federal fits a short-action rifle, but neither matches the 338 Winchester Magnum’s combination of performance and practical accessibility for the hunter who wants one .338-caliber rifle that works from a 50-yard black bear encounter to a 500-yard open-country elk shot.
For related reading, see 338 Winchester Magnum ballistics, 300 Winchester Magnum complete guide, 338 Lapua Magnum complete guide, and 338 Federal complete guide.
Disclaimer: All load data in this article is for reference purposes only. Verify all charges against current published reloading manuals before loading. Large rifle magnum primers are required. Never exceed published maximum charges. Always begin 10% below listed maximums and work up while monitoring for pressure signs.
Editorial note: This article was originally published in January 2026 and revised in April 2026. The revision corrected the recoil figure (28-32 ft-lbs in a 9-lb rifle rather than the original 35 ft-lbs in an 8-lb rifle), corrected the ballistics table to 200-yard zero per site standard, added belted case headspacing and sizing technique guidance, a complete powder table with 15 powders and charge weight ranges, expanded bullet selection with 13 bullets covering deer through dangerous game applications, a four-cartridge comparison table placing the 338 Win Mag in context among .338-caliber options, hunting application guidance by game type including specific dangerous game recommendations, and honest positioning relative to 338 Federal and 338 Lapua Magnum for different buyer needs.
