Rifle · SAAMI
.338 Winchester Magnum
The most versatile dangerous-game cartridge available in standard-length actions.
- Caliber
- 0.338″ · 8.585 mm
- Introduced
- 1958
- Case
- Belted
- Parent
- .375 H&H Magnum
- Primary use
- Hunting, Big Game, Long Range
- Status
- Active
- Introduced
- 1958
- Type
- Rifle
- Origin
- United States
- Inventor
- Winchester
- Manufacturer
- Winchester Ammunition
- Standard
- SAAMI
- Status
- Active
- Availability
- Common
- Case capacity
- 91 gr H₂O
- Twist (typical)
- 1:10
- Primer
- Large Rifle Magnum
- Case type
- Belted
- Max pressure
- 64,000 psi
- Eff. range
- 500 yd
- Max range
- 1500 yd
- Recoil
- 20–28 ft·lb
Introduced by Winchester Ammunition
Ballistics
Real trajectory computed from a representative load — Nosler Trophy Grade 225 gr, 2,750 fps, BC 0.550 G1 · 100 yd zero · sight height 1.5 in.
| Range | Velocity | Energy | Drop (in) | Drop (MOA) |
|---|---|---|---|---|
| 0 yd | 2750 | 3778 | -1.5″ | — |
| 100 yd | 2660 | 3534 | 0.0″ | 0.0 |
| 200 yd | 2571 | 3302 | -3.4″ | -1.6 |
| 300 yd | 2483 | 3081 | -12.1″ | -3.8 |
| 400 yd | 2397 | 2870 | -26.4″ | -6.3 |
| 500 yd | 2312 | 2670 | -46.8″ | -8.9 |
| 600 yd | 2228 | 2480 | -73.6″ | -11.7 |
| 700 yd | 2146 | 2300 | -107.5″ | -14.7 |
| 800 yd | 2065 | 2129 | -149.0″ | -17.8 |
Point-mass G7/G1 drag model, standard atmosphere — within ~2% of reference solvers to 1000 yd; real barrels and conditions vary. Open in Ballistic Compare →
Performance
Dimensionscase measurements · scale drawing · size vs familiar rounds
Case dimensions — the scale drawing at the top of the page is built from these.
SAAMI · verified| Measure | mm | in | ✓ |
|---|---|---|---|
| Bullet ⌀ | 8.59 | 0.338 | ✓ |
| Neck ⌀ | 9.37 | 0.369 | ✓ |
| Shoulder ⌀ | 12.47 | 0.491 | ✓ |
| Shoulder angle | 25° | — | ✓ |
| Base ⌀ | 13.03 | 0.513 | ✓ |
| Rim ⌀ | 13.51 | 0.532 | ✓ |
| Belt ⌀ | 13.51 | 0.532 | ~ |
| Rim thickness | 1.27 | 0.050 | ✓ |
| Neck length | 8.38 | 0.330 | ≈ |
| Case length | 63.50 | 2.500 | ✓ |
| Overall length | 84.84 | 3.340 | ✓ |
Size vs familiar rounds
Drawn at true 1:1 — every case is accurate relative to the others. Absolute size depends on your screen's pixel density, so measuring one against a real ruler may be off. .338 Winchester Magnum is highlighted below.
Factory loads
In production — 124 active loads across 21 brands. Top 2 shown · see all 127 →.
| Brand | Load | Grain | Bullet | FPS | ft·lb | BC |
|---|---|---|---|---|---|---|
| Nosler | Trophy Grade | 225 | AccuBond | 2,750 | 3,778 | 0.550 G1 |
| Nosler | Expansion Tip | 225 | E-Tip | 2,750 | 3,778 | — |
Velocities are manufacturer-stated (test-barrel). Discontinued loads are shaded and marked.
Suitable powders
23 reloading powders listed for .338 Winchester Magnum, fastest to slowest. Cross-reference in the finder →
Reloading costestimate cost per round vs factory
Estimate your cost per round and how it compares to factory. Inputs are yours — nothing is stored.
Cost estimate only — not load data. Charge weight is your input; follow published manuals for safe charges.
Firearms chambered in .338 Winchester Magnum
12 models in the database chamber .338 Winchester Magnum. Browse all →
Lineage
Connected reference
History
Introduced by Winchester in 1958 on the .375 H&H case. Immediately became the premium American big-game cartridge. Jack O'Connor and Elmer Keith debated it — O'Connor preferred his 7mm; Keith thought it perfect for heavy game.
FAQs
- What twist rate does .338 Winchester Magnum use?
- .338 Winchester Magnum typically uses a 1:10 twist rate.
- What bullet diameter is .338 Winchester Magnum?
- .338 Winchester Magnum uses a 0.338″ (8.585 mm) diameter bullet.
- Is .338 Winchester Magnum still in production?
- .338 Winchester Magnum is active; typical availability is common.
- What is .338 Winchester Magnum used for?
- .338 Winchester Magnum is primarily used for hunting, big game, long range.
- What is .338 Winchester Magnum based on?
- .338 Winchester Magnum is derived from the .375 H&H Magnum case.
- What are the best powders for .338 Winchester Magnum?
- Reloading powders commonly listed for .338 Winchester Magnum include N550, 203-B, N540, Accurate 4350, among 23 suitable options.
Sources & provenance
- Standard SAAMI — SAAMI cartridge & chamber drawing — .338 Winchester Magnum archived
- Standard SAAMI — ANSI/SAAMI Z299 — Cartridge & Chamber Drawings archived
- Manufacturer Federal Premium — Trophy Bonded Tip 338 Win Mag 200 Grain (P338TT2) · grain_ballistics, representative_gun archived
- Manufacturer Hornady — 338 Win Mag 200 gr SST Superformance · grain_ballistics, representative_gun archived
- Manufacturer Remington — Core-Lokt 338 Win Mag Ammo, 225 Grain · grain_ballistics, representative_gun archived
- Manufacturer Hornady — 338 Win Mag 225 gr SST Superformance · grain_ballistics, representative_gun archived
- Manufacturer Nosler — 338 Win Mag 225gr AccuBond Trophy Grade Ammunition · grain_ballistics, representative_gun archived
- Manufacturer Remington — Core-Lokt 338 Win Mag Ammo, 250 Grain · grain_ballistics, representative_gun archived
- Manufacturer Nosler — 338 Win Mag 250gr AccuBond Trophy Grade Ammunition · grain_ballistics, representative_gun archived
Data & sources. Specs compiled from the Lindcott Armory reference; availability counted from 124 live factory loads; the trajectory is modeled (point-mass), not measured. See methodology. Spotted an error? Report it →