History
A 1980s military requirement set the brief: reach past the .300 Winchester Magnum and defeat hard targets at 1,000 metres and beyond. Lapua finalized the design, and C.I.P. standardized it in 1989. It became the dominant Western military long-range cartridge, the answer between the .300 magnums and the .50 BMG, and it has held that ground for decades.
A 250 to 300 grain bullet at this velocity stays supersonic well past 1,500 yards, and the cartridge has featured in some of the longest confirmed shots on record. It is the benchmark by which ELR .338s are measured.
Lineage
The parent is the big beltless .416 Rigby case, shortened and strengthened for high pressure, then necked to a .338 inch (8.59mm) bullet. With no belt it headspaces on the shoulder, and the case head runs near .588 inch. Its closest relative is the more efficient .338 Norma Magnum, which folds similar performance into a shorter case; the .300 Norma and the .375 and .408 CheyTac round out the company it keeps at extreme range.
Specifications
| Spec | Value |
|---|---|
| Case type | Rimless, bottlenecked (beltless magnum) |
| Bullet diameter | 8.59 mm (.338 in) |
| Neck diameter | 9.44 mm (.3717 in) |
| Shoulder diameter | 13.81 mm (.5437 in) |
| Base diameter | 14.93 mm (.588 in) |
| Case length | 69.20 mm (2.724 in) |
| Overall length | 93.50 mm (3.681 in) |
| Case capacity | ~114 gr H2O (nominal; varies by brand) |
| Primer size | Large rifle magnum |
| Belted | No |
| Rifling twist | 1 in 9 in (C.I.P. reference standard) |
| Max pressure | 60,916 psi / 4,200 bar (C.I.P.) |
| Recommended barrel | 36 in, 1:9 twist |
Barrel Design
This is a large, overbore ELR case built to be shot from long barrels. Military and competition rifles routinely wear 27 to 36 inches, because the slow powders this case burns keep adding velocity well down the bore. For the extreme-long-range mission this site is built around, I set the baseline at 36 inches, which collects the velocity the cartridge is designed for and tightens standard deviation, the metric that decides hits at a mile.
Twist should be 1:9 to stabilize the heavy 250 to 300 grain match bullets that define the cartridge. These are long and high-BC, and a 1:9 holds them with the margin to stay stable through the transonic transition at extreme range. Some makers run 1:10, which works with the lighter 250s, but 1:9 covers the full span to 300 grains.
A short barrel throws away the velocity the whole cartridge exists to make, and the recoil and blast only worsen for the trade. The tables below are computed at the 36 inch baseline.
Range Ammo Performance
Sellier & Bellot · 250 gr Sierra MatchKing HPBT $2.90/rd
| Range (yd) | Velocity (fps) | Elevation (mil) | Energy (ft-lb) | Windage (mil) |
|---|---|---|---|---|
| 0 | 3028 | -0.3 | 5089 | 0.3 |
| 100 | 2891 | 0.0 | 4639 | 0.2 |
| 200 | 2757 | -0.3 | 4219 | 0.3 |
| 300 | 2626 | -0.8 | 3828 | 0.5 |
| 400 | 2499 | -1.4 | 3466 | 0.6 |
| 500 | 2375 | -2.1 | 3132 | 0.8 |
| 600 | 2255 | -2.9 | 2823 | 1.0 |
| 700 | 2139 | -3.7 | 2539 | 1.2 |
| 800 | 2026 | -4.5 | 2278 | 1.4 |
| 900 | 1916 | -5.5 | 2038 | 1.6 |
| 1000 | 1810 | -6.5 | 1817 | 1.9 |
| 1100 | 1705 | -7.6 | 1614 | 2.1 |
| 1200 | 1604 | -8.8 | 1428 | 2.4 |
| 1300 | 1505 | -10.2 | 1257 | 2.7 |
| 1400 | 1409 | -11.6 | 1102 | 3.0 |
| 1500 | 1316 | -13.2 | 962 | 3.3 |
| 1600 | 1227 | -14.9 | 836 | 3.7 |
| 1700 | 1144 | -16.8 | 727 | 4.1 |
| 1800 | 1086 | -19.0 | 654 | 4.5 |
| 1900 | 1052 | -21.3 | 614 | 4.9 |
| 2000 | 1024 | -23.9 | 582 | 5.4 |
| 2100 | 1000 | -26.6 | 555 | 5.8 |
| 2200 | 977 | -29.6 | 530 | 6.2 |
| 2300 | 956 | -32.7 | 507 | 6.6 |
| 2400 | 936 | -36.1 | 486 | 7.0 |
| 2500 | 916 | -39.6 | 466 | 7.4 |
| 2600 | 898 | -43.3 | 447 | 7.9 |
| 2700 | 880 | -47.2 | 430 | 8.3 |
| 2800 | 862 | -51.3 | 413 | 8.7 |
Muzzle velocity 3028 fps is estimated at 36 in from the 26 in factory figure of 2848 fps at about 18 fps per inch. Expect your own barrel to read a little differently. Velocity is color coded green supersonic, yellow transonic, red subsonic; treat transonic and subsonic rows as approximate.
Match Ammo Performance
Lapua · 300 gr Scenar OTM $7.70/rd
| Range (yd) | Velocity (fps) | Elevation (mil) | Energy (ft-lb) | Windage (mil) |
|---|---|---|---|---|
| 0 | 2852 | -0.3 | 5418 | 0.3 |
| 100 | 2732 | 0.0 | 4972 | 0.2 |
| 200 | 2615 | -0.3 | 4555 | 0.3 |
| 300 | 2501 | -0.9 | 4165 | 0.5 |
| 400 | 2389 | -1.6 | 3802 | 0.7 |
| 500 | 2281 | -2.4 | 3464 | 0.9 |
| 600 | 2175 | -3.2 | 3151 | 1.0 |
| 700 | 2073 | -4.1 | 2861 | 1.2 |
| 800 | 1973 | -5.0 | 2592 | 1.5 |
| 900 | 1875 | -6.1 | 2342 | 1.7 |
| 1000 | 1780 | -7.2 | 2110 | 1.9 |
| 1100 | 1687 | -8.3 | 1895 | 2.2 |
| 1200 | 1596 | -9.6 | 1696 | 2.4 |
| 1300 | 1507 | -11.0 | 1512 | 2.7 |
| 1400 | 1420 | -12.5 | 1344 | 3.0 |
| 1500 | 1336 | -14.1 | 1189 | 3.4 |
| 1600 | 1255 | -15.8 | 1050 | 3.7 |
| 1700 | 1178 | -17.8 | 925 | 4.1 |
| 1800 | 1111 | -19.9 | 822 | 4.5 |
| 1900 | 1072 | -22.2 | 765 | 4.9 |
| 2000 | 1044 | -24.7 | 726 | 5.3 |
| 2100 | 1020 | -27.4 | 693 | 5.8 |
| 2200 | 998 | -30.2 | 664 | 6.2 |
| 2300 | 978 | -33.3 | 637 | 6.6 |
| 2400 | 959 | -36.5 | 613 | 7.0 |
| 2500 | 941 | -39.9 | 590 | 7.4 |
| 2600 | 923 | -43.5 | 568 | 7.8 |
| 2700 | 907 | -47.3 | 547 | 8.2 |
| 2800 | 890 | -51.2 | 528 | 8.6 |
Muzzle velocity 2852 fps is estimated at 36 in from the 27 in factory figure of 2690 fps at about 18 fps per inch. Expect your own barrel to read a little differently. Velocity is color coded green supersonic, yellow transonic, red subsonic; treat transonic and subsonic rows as approximate.
Trajectory
FAQ
What barrel length and twist should I run?
A long 30 to 36 inch barrel and a 1:9 twist. The length delivers the velocity this overbore ELR case is built for, and the twist stabilizes the heavy 250 to 300 grain match bullets through the transonic range at extreme distance.
How does it compare to the .338 Norma Magnum?
The .338 Norma fits nearly the same performance into a shorter case that fits a standard-length action and is a touch more efficient. The .338 Lapua has the larger case, the longer track record, and far broader factory ammunition and rifle support. For most shooters the Lapua is the easier cartridge to buy into.
What is the .338 Lapua Magnum good for?
Extreme-long-range and a-mile-plus precision, military and competition, and the largest game at distance. Its retained supersonic velocity and high-BC heavy bullets are the point; it is far more cartridge, recoil, and cost than ordinary hunting needs.
How much does it recoil?
A lot. In a typical rifle the .338 Lapua generates roughly twice the recoil energy of a .300 Win Mag, which is why these rifles are heavy and almost always muzzle-braked. It is a cartridge you set up a rifle around, not one you add to a light hunting gun.