Lindcott Armory Rifle · SAAMI
.300 Remington Ultra Magnum
Remington's most powerful .30-caliber commercial cartridge.
- Caliber
- 0.308″ · 7.823 mm
- Introduced
- 1999
- Case
- Rebated
- Parent
- .404 Jeffery
- Primary use
- Hunting, Target
- Status
- Active
- Introduced
- 1999
- Type
- Rifle
- Origin
- United States
- Inventor
- Remington Arms
- Manufacturer
- Remington / Federal / Hornady
- Standard
- SAAMI
- Status
- Active
- Availability
- Specialty
- Case capacity
- 115 gr H₂O
- Twist (typical)
- 1:10
- Primer
- Large Rifle Magnum
- Case type
- Rebated
- Max pressure
- 65,000 psi
- Eff. range
- 600 yd
- Max range
- 1500 yd
- Recoil
- 28–40 ft·lb
Ballistics
Real trajectory computed from a representative load — Berger Hunting 215 gr, 3,000 fps, BC 0.354 G7 · 100 yd zero.
| Range | Velocity | Energy | Drop (in) | Drop (MOA) |
|---|---|---|---|---|
| 0 yd | 2999 | 4294 | -1.5″ | — |
| 100 yd | 2867 | 3922 | 0.0″ | 0.0 |
| 200 yd | 2737 | 3575 | -2.7″ | -1.3 |
| 300 yd | 2610 | 3251 | -10.1″ | -3.2 |
| 400 yd | 2486 | 2950 | -22.6″ | -5.4 |
| 500 yd | 2365 | 2669 | -40.7″ | -7.8 |
| 600 yd | 2247 | 2411 | -65.1″ | -10.4 |
| 700 yd | 2133 | 2172 | -96.3″ | -13.1 |
| 800 yd | 2022 | 1951 | -135.2″ | -16.1 |
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
Buy links open .300 Remington Ultra Magnum ammunition at Rivertown Munitions.
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 ⌀ | 7.82 | 0.308 | ✓ |
| Neck ⌀ | 8.74 | 0.344 | ✓ |
| Shoulder ⌀ | 13.34 | 0.525 | ✓ |
| Shoulder angle | 30° | — | ✓ |
| Base ⌀ | 13.97 | 0.550 | ✓ |
| Rim ⌀ | 13.56 | 0.534 | ✓ |
| Belt ⌀ | n/a | ||
| Rim thickness | 1.27 | 0.050 | ~ |
| Neck length | 7.77 | 0.306 | ≈ |
| Case length | 72.39 | 2.850 | ✓ |
| Overall length | 91.44 | 3.600 | ✓ |
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. .300 Remington Ultra Magnum is highlighted below.
Factory loads
In production — 23 active loads across 8 brands. Top 15 shown · see all 23 →.
| Brand | Load | Grain | Bullet | FPS | ft·lb | BC |
|---|---|---|---|---|---|---|
| Hornady | American Whitetail Interlock SP | 165 | Interlock SP | 3,400 | 4,235 | 0.447 G1 |
| Nosler | Trophy Grade AccuBond | 180 | AccuBond | 3,250 | 4,221 | 0.259 G7 |
| Remington | Premier AccuTip | 180 | AccuTip BT | 3,250 | 4,221 | 0.480 G1 |
| Hornady | Precision Hunter ELD-X | 178 | ELD-X | 3,250 | 4,174 | 0.287 G7 |
| Barnes | VOR-TX | 180 | TTSX BT | 3,250 | 4,221 | 0.235 G7 |
| Winchester | Expedition Big Game | 180 | AccuBond CT | 3,250 | 4,221 | 0.259 G7 |
| Hornady | Precision Hunter ELD-X | 220 | ELD-X | 3,150 | 4,846 | 0.336 G7 |
| Nosler | Trophy Grade AccuBond Long Range | 210 | AccuBond LR | 3,100 | 4,480 | 0.350 G7 |
| Winchester | Expedition Big Game | 180 | Nosler AccuBond | 3,025 | 3,657 | 0.259 G7 |
| HSM | Trophy Gold | 210 | Berger VLD | 3,025 | 4,266 | 0.317 G7 |
| Winchester | AccuBond CT | 180 | Nosler AccuBond CT | 3,025 | 3,657 | 0.259 G7 |
| Barnes | LRX BT | 200 | LRX BT | 3,025 | 4,063 | 0.288 G7 |
| Hornady | Precision Hunter | 212 | ELD-X | 3,010 | 4,264 | 0.350 G7 |
| Berger | Hunting | 215 | Hybrid Hunter | 3,000 | 4,296 | 0.354 G7 |
| Remington | Core-Lokt Ultra Bonded | 180 | PSP Bonded | 3,250 | 4,221 | — |
Velocities are manufacturer-stated (test-barrel). Discontinued loads dimmed.
Suitable powders
6 reloading powders listed for .300 Remington Ultra 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 .300 Remington Ultra Magnum
12 models in the database chamber .300 Remington Ultra Magnum. Browse all →
Lineage
Connected reference
History
Remington introduced the Ultra Mag family in 1999–2000 on a large rebated-rim case that fit standard-length bolt faces. The .300 RUM pushed 180-grain bullets to 3,250 fps, delivering flat trajectories and long-range terminal energy for elk, moose, and large bears. The main limitation is barrel erosion: the high velocity and large powder charge accelerate throat wear significantly. Remington, Federal, and Hornady produce factory ammunition. The Model 700 in .300 RUM remains the primary platform.
FAQs
- What twist rate does .300 Remington Ultra Magnum use?
- .300 Remington Ultra Magnum typically uses a 1:10 twist rate.
- What bullet diameter is .300 Remington Ultra Magnum?
- .300 Remington Ultra Magnum uses a 0.308″ (7.823 mm) diameter bullet.
- Is .300 Remington Ultra Magnum still in production?
- .300 Remington Ultra Magnum is active; typical availability is specialty.
- What is .300 Remington Ultra Magnum used for?
- .300 Remington Ultra Magnum is primarily used for hunting, target.
- What is .300 Remington Ultra Magnum based on?
- .300 Remington Ultra Magnum is derived from the 7mm Remington Magnum case.
- What are the best powders for .300 Remington Ultra Magnum?
- Reloading powders commonly listed for .300 Remington Ultra Magnum include Retumbo, AR 2218, Reloader 25, Reloader 26, among 6 suitable options.
Sources & provenance
- StandardSAAMI — SAAMI cartridge & chamber drawing — .300 Remington Ultra Magnumarchived
- StandardSAAMI — ANSI/SAAMI Z299 — Cartridge & Chamber Drawingsarchived
- Secondary.300 Remington Ultra Magnum - Wikipedia · parent_cartridge
- Secondary.300 RUM - Remington's Ultra Magnum (Lynx Defense) · parent_cartridge
Data & sources. Specs compiled from the Lindcott Armory reference; availability counted from 23 live factory loads; the trajectory is modeled (point-mass), not measured. See methodology. Spotted an error? Report it →