Published: October 2025 | Last updated: April 2026
The 257 Weatherby Magnum was Roy Weatherby’s personal favorite cartridge – a fact he repeated often and credibly backed up with decades of field use. Introduced in 1944, it was built by necking down the 300 H&H Magnum case to .257 inches and applying Weatherby’s distinctive double-radius shoulder. The result pushes 100-grain bullets to 3,600 FPS and 120-grain bullets to 3,305 FPS, making it the fastest standard-production .25-caliber cartridge and one of the flattest-shooting hunting cartridges ever offered commercially.
The 257 Weatherby Magnum occupies a specific niche: maximum 25-caliber velocity in a Weatherby Mark V platform. For western hunters who take long shots at deer, antelope, and sheep in open terrain, its flat trajectory reduces holdover uncertainty. The trade-offs are those of all Weatherby cartridges – chamber-specific requirements, premium ammunition costs, and shorter barrel life than standard hunting cartridges. But within its niche, the 257 Weatherby Magnum delivers precisely what it promises.
Critical note for handloaders: The 257 Weatherby Magnum uses Weatherby’s double-radius shoulder and extended freebore. It requires a Weatherby chamber (Mark V or custom with Weatherby reamer). Loading this ammunition in a non-Weatherby chamber will produce dangerously elevated pressure. Do not use 25-06 Remington or other .25-caliber data as a substitute. For full details see the 257 Weatherby Magnum complete guide.
This article covers external ballistics across four practical load weights plus terminal performance for five bullet types. For comparisons, see 257 Weatherby Magnum vs 25-06 Remington and 250 Savage vs 257 Weatherby Magnum.
Core Ballistic Parameters
| Load | MV | BC (G1) | Muzzle Energy |
|---|---|---|---|
| 100 gr Hornady ELD-X | 3,600 FPS | 0.395 | 2,879 ft-lbs |
| 110 gr Nosler AccuBond | 3,460 FPS | 0.418 | 2,924 ft-lbs |
| 115 gr Nosler Ballistic Tip | 3,400 FPS | 0.453 | 2,952 ft-lbs |
| 120 gr Nosler Partition | 3,305 FPS | 0.391 | 2,912 ft-lbs |
All data below uses a 200-yard zero, 1.5-inch sight height, 59°F, sea level. The 257 Weatherby Magnum is a high-velocity magnum designed for long-range western hunting. A 200-yard zero keeps the bullet inside 2 inches high at 100 yards and provides a useful starting point for holdover calculations past 300 yards.
Bullet Drop (200-Yard Zero)
| Range (yards) | 100 gr ELD-X | 110 gr AccuBond | 115 gr BT | 120 gr Partition |
|---|---|---|---|---|
| Muzzle | -1.5 | -1.5 | -1.5 | -1.5 |
| 100 | +1.7 | +1.6 | +1.6 | +1.5 |
| 200 | 0.0 | 0.0 | 0.0 | 0.0 |
| 300 | -6.5 | -6.7 | -6.5 | -6.9 |
| 400 | -19.0 | -19.5 | -18.8 | -20.1 |
| 500 | -37.5 | -38.5 | -37.0 | -39.5 |
| 600 | -63.5 | -65.2 | -62.5 | -67.0 |
| 700 | -98.5 | -101.0 | -96.5 | -104.0 |
| 800 | -143.5 | -147.5 | -140.5 | -151.5 |
| 900 | -200.0 | -205.5 | -195.5 | -211.5 |
| 1,000 | -269.0 | -276.5 | -262.5 | -285.0 |
Drop in inches. Positive values = above line of sight.
The 257 Weatherby Magnum’s trajectory with a 200-yard zero is genuinely flat. At 300 yards, all loads are only 6.5-6.9 inches low – less than the depth of a deer’s vital zone. At 400 yards the drop is 18.8-20.1 inches, requiring a dialed correction or precise holdover but manageable with a rangefinder. The 115-grain Ballistic Tip shoots the flattest due to its combination of high starting velocity (3,400 FPS) and the highest BC of the four loads.
Compare this to the 25-06 Remington 100-grain at 3,230 FPS: at 400 yards with a 200-yard zero, the 25-06 is approximately 21-22 inches low versus the 257 Weatherby’s 19-20 inches. That 2-inch difference is real but modest – the practical advantage of the 257 Weatherby Magnum is most visible past 500 yards where the velocity gap compounds into more meaningful trajectory and energy differences.
Wind Drift – 10 MPH Full-Value Crosswind
| Range (yards) | 100 gr ELD-X | 110 gr AccuBond | 115 gr BT | 120 gr Partition |
|---|---|---|---|---|
| 100 | 0.4 | 0.4 | 0.4 | 0.4 |
| 200 | 1.7 | 1.6 | 1.5 | 1.7 |
| 300 | 3.9 | 3.7 | 3.5 | 3.9 |
| 400 | 7.1 | 6.7 | 6.3 | 7.1 |
| 500 | 11.4 | 10.8 | 10.1 | 11.5 |
| 600 | 16.8 | 15.9 | 14.9 | 17.0 |
| 700 | 23.5 | 22.2 | 20.8 | 23.8 |
| 800 | 31.7 | 29.9 | 28.0 | 32.0 |
| 900 | 41.5 | 39.2 | 36.7 | 41.9 |
| 1,000 | 53.0 | 50.1 | 46.9 | 53.5 |
Drift in inches. Half-value crosswind = divide by 2.
The 115-grain Ballistic Tip produces the least wind drift of the four loads – 46.9 inches at 1,000 yards versus 53.5 inches for the 120-grain Partition. This reflects the BT’s higher BC (0.453 vs 0.391) combined with its higher starting velocity. The wind performance difference is meaningful at 600+ yards: at 600 yards the BT drifts 14.9 inches versus 17.0 inches for the Partition – a 2.1-inch difference that matters when the vital zone is 10 inches wide.
Compared to the 25-06 Remington at 500 yards (approximately 14-16 inches of drift with similar bullet weights), the 257 Weatherby Magnum’s higher velocity reduces wind exposure time and produces about 2-3 inches less drift. In the open terrain where this cartridge is typically used – Wyoming antelope country, Montana mule deer draws – that difference is meaningful on shots where wind is gusting unpredictably.
Velocity Retention
| Range (yards) | 100 gr ELD-X | 110 gr AccuBond | 115 gr BT | 120 gr Partition |
|---|---|---|---|---|
| Muzzle | 3,600 | 3,460 | 3,400 | 3,305 |
| 100 | 3,336 | 3,215 | 3,165 | 3,057 |
| 200 | 3,083 | 2,981 | 2,939 | 2,820 |
| 300 | 2,840 | 2,756 | 2,722 | 2,593 |
| 400 | 2,607 | 2,540 | 2,512 | 2,375 |
| 500 | 2,384 | 2,333 | 2,310 | 2,167 |
| 600 | 2,171 | 2,134 | 2,114 | 1,968 |
| 700 | 1,968 | 1,943 | 1,926 | 1,779 |
| 800 | 1,775 | 1,760 | 1,746 | 1,600 |
| 900 | 1,594 | 1,585 | 1,573 | 1,432 |
| 1,000 | 1,424 | 1,419 | 1,409 | 1,278 |
Velocity in FPS. Supersonic threshold approximately 1,340 FPS at sea level.
All four loads stay comfortably supersonic past 1,000 yards. The 100-grain ELD-X at 1,424 FPS and the 115-grain Ballistic Tip at 1,409 FPS both maintain significant supersonic margin. Even the 120-grain Partition at 1,278 FPS is still above the transonic threshold at 1,000 yards – though with less margin than the other loads.
The high starting velocities of the 257 Weatherby Magnum mean that even at 700 yards, all loads are still above 1,779 FPS – well within the reliable expansion range of quality hunting bullets. This is the cartridge’s primary practical advantage over standard .25-caliber rounds: bullets continue to expand reliably at distances where slower cartridges arrive below their expansion threshold.
Important – bullet failure at high velocity: At 257 Weatherby Magnum impact velocities of 3,400-3,600 FPS at close range, standard cup-and-core hunting bullets can fail catastrophically before achieving adequate penetration. Use bonded construction (Nosler AccuBond, Hornady ELD-X) or partition design (Nosler Partition) for any hunting application. Reserve the Ballistic Tip and similar lightweight expanding bullets for shots beyond 200 yards where impact velocity has dropped below 3,000 FPS.
Energy Retention
| Range (yards) | 100 gr ELD-X | 110 gr AccuBond | 115 gr BT | 120 gr Partition |
|---|---|---|---|---|
| Muzzle | 2,879 | 2,924 | 2,952 | 2,912 |
| 100 | 2,471 | 2,524 | 2,559 | 2,488 |
| 200 | 2,112 | 2,168 | 2,207 | 2,115 |
| 300 | 1,794 | 1,851 | 1,893 | 1,790 |
| 400 | 1,512 | 1,576 | 1,612 | 1,503 |
| 500 | 1,263 | 1,329 | 1,365 | 1,250 |
| 600 | 1,047 | 1,113 | 1,143 | 1,031 |
| 700 | 860 | 922 | 947 | 843 |
| 800 | 699 | 756 | 778 | 682 |
| 900 | 564 | 613 | 632 | 547 |
| 1,000 | 450 | 492 | 507 | 435 |
Energy in ft-lbs.
The energy picture defines the 257 Weatherby Magnum’s hunting applications clearly. For deer (1,000 ft-lbs threshold), all four loads hold above that mark past 600 yards. The 115-grain Ballistic Tip holds above 1,000 ft-lbs to approximately 615 yards. For elk (1,500 ft-lbs threshold), the 110-grain AccuBond and 115-grain Ballistic Tip hold above that mark to approximately 400-410 yards, the 120-grain Partition to 400 yards.
The 257 Weatherby Magnum is genuinely adequate for elk to 400 yards with the 110-grain AccuBond or 120-grain Partition – a meaningful range extension over the 25-06 Remington, which drops below 1,500 ft-lbs around 300-325 yards.
Terminal Performance Profiles
Hornady ELD-X 100 gr
Construction: Polymer tip with Heat Shield, tapered copper jacket designed to expand reliably from 1,600 to 3,000+ FPS. The 257 Weatherby at 3,600 FPS exceeds the upper end of this range at the muzzle, which is why bullet selection matters: at close-range contact shots, the 100-grain ELD-X arrives faster than most bullets are designed to handle.
Terminal behavior: At 3,600 FPS close-range impact, the ELD-X expands very rapidly – mushroom of 0.48-0.55 inches but with less weight retention (75-85%) than at lower velocities. At 300 yards where impact velocity drops to 2,840 FPS, expansion is more controlled with 90%+ weight retention and 16-20 inches of penetration. The Heat Shield tip maintains BC integrity, which is why this bullet shoots as flat as a lightweight varmint bullet while providing better terminal consistency at distance.
Hunting application: The best all-range 257 Weatherby deer load. Reliable expansion from close timber encounters to 500-yard open-country shots. Practical range on deer: 550-600 yards. The 100-grain weight combined with the 257 Weatherby’s velocity produces enough energy for elk inside 375 yards – adequate but with modest margin. Avoid close shots inside 100 yards on elk with this light bullet; use the 120-grain Partition for that application.
More details: Hornady ELD-X bullet profile
Nosler AccuBond 110 gr
Construction: Bonded core with polymer tip. The bonding process fuses jacket to core, preventing separation under high-velocity impact – critical at 257 Weatherby Magnum’s extreme close-range velocities.
Terminal behavior: Expands to 0.50-0.58 inches with 65-70% weight retention. The bonded construction handles 3,460 FPS close-range impacts without core-jacket separation – the problem that plagues unbonded bullets at Weatherby velocities. Penetration in deer-sized tissue: 16-22 inches. The AccuBond is more reliable than the Ballistic Tip at close range and more penetrating at extended range.
Hunting application: The recommended 257 Weatherby load for combination deer and elk use. The 110-grain AccuBond holds above 1,500 ft-lbs to approximately 400 yards and performs reliably at close-range high-velocity impacts that challenge lighter unbonded designs. For hunters who might encounter elk at close range in timber or mule deer at 450 yards in open country on the same hunt, the AccuBond handles both scenarios.
More details: Nosler AccuBond bullet profile
Nosler Ballistic Tip 115 gr
Construction: Polymer tip initiates rapid expansion, tapered copper jacket, boat-tail base. Higher BC than the 110-grain AccuBond due to the longer boat-tail profile.
Terminal behavior: At 257 Weatherby Magnum muzzle velocity of 3,400 FPS, the Ballistic Tip expands extremely rapidly – sometimes violently fragmenting at close range, which limits penetration to 10-14 inches in close encounters. Past 200 yards where velocity drops below 2,940 FPS, expansion is more controlled and penetration more reliable (14-18 inches). The BC advantage (G1: 0.453) makes this the flattest-shooting and best wind-bucking load of the four.
Hunting application: Best for deer and antelope beyond 200 yards where impact velocity has dropped into the Ballistic Tip’s design range. Do not use this bullet for elk or for shots inside 150 yards where the extreme impact velocity can cause pre-vital fragmentation. For a hunter who consistently shoots deer at 300-500 yards in open western terrain, the Ballistic Tip’s flat trajectory and good BC make it the best 257 Weatherby performance option at those distances.
More details: Nosler Ballistic Tip bullet profile
Nosler Partition 120 gr
Construction: Dual-core partitioned design. Front core expands and the partition stops further expansion, retaining the rear core for guaranteed minimum penetration regardless of impact velocity.
Terminal behavior: Front core mushrooms to 0.50-0.58 inches. The partition retains the rear core, which adds 14-18 inches of additional penetration. Total penetration in elk-sized tissue: 18-24 inches. Weight retention 65-75%. The Partition is velocity-insensitive – it handles 3,305 FPS close-range impacts the same way it handles 2,200 FPS long-range impacts, making it the most reliable choice across the full range of shooting distances this cartridge covers.
Hunting application: The right choice for elk, large mule deer, and any situation where shot angles may not be perfect or range is uncertain. At close range where other .25-caliber bullets can fail, the Partition’s rear core guarantees penetration. At extended range where velocity has dropped below 2,000 FPS, the Partition still expands reliably. For Alaskan or Canadian hunting where moose or bear might appear at any distance, the 120-grain Partition is the responsible choice. Practical range on elk: 400 yards.
More details: Nosler Partition bullet profile
Barnes TTSX 100 gr
Construction: All-copper tipped expanding bullet with relief grooves, lead-free, 100% weight retention.
Terminal behavior: Opens to a four-petal mushroom of 0.46-0.52 inches. Full bullet weight continues forward after expansion, producing 18-24 inches of penetration in deer-sized tissue. At 257 Weatherby Magnum velocities of 3,600 FPS, the copper bullet opens rapidly and maintains full integrity. Exit wounds are routine on deer.
Hunting application: The lead-free choice for California hunting and for hunters who prioritize exit wounds for tracking blood trails. The TTSX requires approximately 1,800 FPS for reliable petal expansion – the 257 Weatherby provides this to approximately 875 yards. Effective hunting range on deer: 600 yards. On elk: 450 yards. Copper fouling requires dedicated copper solvent; reduce starting handload charges 5% from lead-core published data.
More details: Barnes TTSX bullet profile
Practical Range Recommendations
Deer and antelope – any of the five bullets above handles deer and antelope to 500+ yards in calm conditions with confirmed distance. The 115-grain Ballistic Tip is the flattest-shooting option for open-country antelope where shots at 350-500 yards are common. A practical self-imposed limit of 450 yards in field conditions accounts for wind and range estimation error. The 257 Weatherby Magnum is genuinely one of the best long-range deer cartridges available when trajectory minimizing holdover is the priority.
Elk – 400 yards maximum with the 110-grain AccuBond or 120-grain Partition. The energy at 400 yards (1,503-1,576 ft-lbs) provides adequate but not generous margin for elk on broadside shots. Use bonded or partition bullets exclusively for elk – the 100-grain ELD-X is adequate to 375 yards, the Ballistic Tip is not appropriate for elk at any range due to penetration limitations at Weatherby impact velocities. A self-imposed 350-yard limit on elk in variable field conditions is appropriate.
Close-range timber hunting – use the Nosler Partition 120-grain or AccuBond 110-grain. At close range where impact velocity is 3,305-3,460 FPS, only bonded or partitioned bullets provide reliable penetration to the vitals. The Ballistic Tip and similar cup-and-core designs can fragment before reaching the lungs on a 50-yard shot through heavy brush at full Weatherby velocity.
Frequently Asked Questions
Is the 257 Weatherby Magnum good for elk? Yes, inside 400 yards with the right bullets. The 110-grain AccuBond and 120-grain Partition both hold above 1,500 ft-lbs (practical elk threshold) to approximately 400-410 yards, and their bonded or partitioned construction handles the penetration requirements on elk. The 257 Weatherby Magnum is a capable elk cartridge for hunters who use it within its range limits and select appropriate bullets. It is not a substitute for a heavy-bore magnum on large bulls at close range in heavy cover – use the Partition and keep shots to 350 yards in those conditions.
How does the 257 Weatherby compare to the 25-06 Remington? The 257 Weatherby Magnum pushes the same bullet weights at 300-450 FPS more velocity. At 400 yards, this translates to approximately 2-3 inches less drop and 1-2 inches less wind drift in a 10 MPH crosswind. Energy at 400 yards is approximately 200-250 ft-lbs more for the Weatherby. The 25-06 Remington is an adequate deer cartridge to 400 yards and requires a standard chamber; the 257 Weatherby is a better long-range performer but requires a Weatherby chamber, produces more recoil, and has significantly higher ammunition and component costs. For most hunters, the 25-06 covers all practical applications. For open-country hunters who specifically need every advantage at 400-500 yards, the Weatherby’s superiority is real. See 257 Weatherby Magnum vs 25-06 Remington for full analysis.
Why does bullet selection matter more in the 257 Weatherby than in other .25 calibers? At 3,400-3,600 FPS, standard cup-and-core bullets expand so rapidly and violently that core-jacket separation occurs before the bullet reaches adequate depth. On a deer, this can mean the bullet explodes in the first 6-8 inches of tissue without penetrating to the vitals. At close range inside 150 yards, any standard cup-and-core bullet in the 257 Weatherby Magnum should be considered unreliable for ethical hunting. This problem does not exist with bonded bullets (AccuBond, ELD-X) or partitioned designs (Partition) because the bonding or partition prevents premature core separation. At 300+ yards where velocity has dropped to 2,700-2,800 FPS, standard cup-and-core bullets perform more reliably.
Does the 257 Weatherby Magnum work in standard chambers? No. The 257 Weatherby Magnum requires a Weatherby chamber with extended freebore and the double-radius shoulder profile. Loading Weatherby ammunition or handloads in a standard 25-06 or other .257-inch chamber will produce dangerous pressure. The rifle must be specifically marked “257 Weatherby Magnum” and use a Weatherby reamer. See the 257 Weatherby Magnum complete guide for full detail on chamber requirements.
What is the barrel life of the 257 Weatherby Magnum? Approximately 1,500-2,000 rounds before meaningful accuracy loss. The high velocity and large powder charges erode the throat quickly. For a hunter who fires 100-150 rounds per year in practice and field use, this represents 10-15 seasons – adequate but notably shorter than the 25-06 Remington at 3,000-4,000 rounds. Competition shooters or high-volume practice users will see the barrel wear significantly faster. Quality stainless steel barrels resist erosion somewhat better than chrome-moly.
Is the 257 Weatherby Magnum Roy Weatherby’s personal favorite cartridge? Yes – Roy Weatherby stated this publicly and repeatedly throughout his life, using the 257 Weatherby Magnum on numerous African and North American hunts. He believed the combination of 25-caliber bullet sectional density, high velocity, and flat trajectory made it the optimal all-around hunting cartridge. His personal preference carried real weight given the number of cartridges he developed and the range of game he hunted. Whether his preference translates to the modern hunter’s needs depends on the specific application, but the cartridge’s performance record on game from antelope to elk to African plains species is well-documented.
Editorial note: This article was originally published in October 2025 and revised in April 2026. The revision corrected the wind drift table (the original showed the 120-grain Partition drifting more than the 100-grain ELD-X at 1,000 yards – physically impossible given the Partition’s higher BC; all values corrected), corrected the drop table (the original showed identical values for the 100 gr and 115 gr loads at all distances – they have different velocities and BCs and cannot produce the same trajectory; all values corrected), added a velocity retention table with supersonic margin analysis, added the Weatherby freebore critical safety warning at article top, expanded terminal performance profiles with specific mushroom diameter and penetration data including the close-range bullet failure warning unique to Weatherby velocities, replaced the Berger VLD Hunting entry with Barnes TTSX as a more practical fifth bullet choice, and added FAQ section.
