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Common uses: Hunting, Big Game, Long Range
| Type | rifle (centerfire) |
| Typical load | 250gr Remington Core-Lokt PSP |
| Muzzle velocity | 2860 fps |
| Muzzle energy | 4542 ft-lb |
| Published G1 ballistic coefficient | 0.431 |
| Case length | 72 mm |
| Overall length | 95 mm |
| Range (yd) | Velocity (fps) | Energy (ft-lb) | Drop (in) |
|---|---|---|---|
| 0 | 2860 | 4540 | -1.5 |
| 100 | 2643 | 3877 | 0 |
| 200 | 2438 | 3298 | -3.5 |
| 300 | 2241 | 2787 | -12.9 |
| 400 | 2053 | 2339 | -29.2 |
| 500 | 1875 | 1952 | -53.7 |
At 1,000 yards, .338 Ultra Mag (250gr at 2860 fps, 100 yd zero, standard conditions) has a modeled come-up of about 35.7 MOA / 10.4 MIL, retaining 1182 fps (transonic).
| Range (yd) | Velocity (fps) | State | Drop (in) | Elev (MOA) | Elev (MIL) |
|---|---|---|---|---|---|
| 300 | 2241 | Supersonic | -12.9 | 4.1 | 1.19 |
| 400 | 2053 | Supersonic | -29.2 | 7.0 | 2.03 |
| 500 | 1875 | Supersonic | -53.7 | 10.3 | 2.98 |
| 600 | 1708 | Supersonic | -88.2 | 14.0 | 4.09 |
| 700 | 1552 | Supersonic | -134.6 | 18.4 | 5.34 |
| 800 | 1411 | Supersonic | -195.6 | 23.3 | 6.79 |
| 900 | 1286 | Transonic | -274.0 | 29.1 | 8.46 |
| 1000 | 1182 | Transonic | -373.4 | 35.7 | 10.37 |
Extended predictions beyond 500 yards are modeled from the same G1 engine — useful for initial DOPE, but outside the 500-yard manufacturer-table validation audit. Confirm with observed DOPE, especially near transonic.
A retained-energy reference only — not a shoot/don't-shoot distance. Real effective range depends on your accuracy, shot placement, bullet construction, and conditions. The ~1,000 ft-lb (deer-sized) and ~1,500 ft-lb (elk-sized) figures are commonly cited rules of thumb, not standards.
Your barrel, ammunition lot, and conditions will differ — always verify against the manufacturer's data and your own rifle.
The .338 RUM is a hard-hitting big-game cartridge built to push heavy .338 bullets at high velocity, making it well suited to elk, moose, large bears, and other tough animals at extended range. Its combination of bullet weight, sectional density, and energy gives it deep penetration and a flatter trajectory than most standard .33-caliber options, which is why it appeals to hunters who want reach and terminal authority in one round. That performance comes at a cost: recoil is substantial, muzzle blast is heavy, and its large powder charge tends to shorten barrel life compared with milder cartridges. It is best paired with a well-fitted rifle and a good recoil pad rather than treated as an all-day plinking round. Factory ammunition and rifle availability are more limited than for mainstream magnums, so many shooters who run it also handload.
Remington introduced the .338 Remington Ultra Magnum in the early 2000s as part of its beltless Ultra Magnum family, which traces its lineage to the large .404 Jeffery case. It was formed by necking up the .300 Remington Ultra Magnum case to accept .338-caliber bullets, giving it a very large powder capacity without the belt found on older magnums built on the .375 H&H case. The design aimed to deliver maximum velocity and energy with heavy .338 bullets, positioning it among the most powerful .338 magnums that still function in a standard-length action.
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