HomeBrowse Calibers › .257 Roberts

.257 Roberts Ballistics — Velocity, Energy & Drop

Common uses: Hunting, Varmint

Specifications

Typerifle (centerfire)
Typical load120gr Federal Premium Vital-Shok Nosler Partition
Muzzle velocity2780 fps
Muzzle energy2060 ft-lb
Published G1 ballistic coefficient0.391
Case length56.72 mm
Overall length70.61 mm
SAAMI max pressure54000 PSI
Common twist rate1:10"

.257 Roberts Trajectory Table

Range (yd)Velocity (fps)Energy (ft-lb)Drop (in)
027802059-1.5
100254617270
20023241439-3.9
30021141191-14.2
4001914976-32.4
5001728795-60.1

.257 Roberts Extended Ballistics (to 1,000 yd)

At 1,000 yards, .257 Roberts (120gr at 2780 fps, 100 yd zero, standard conditions) has a modeled come-up of about 41.8 MOA / 12.1 MIL, retaining 1072 fps (subsonic).

Range (yd)Velocity (fps)StateDrop (in)Elev (MOA)Elev (MIL)
3002114Supersonic-14.24.51.32
4001914Supersonic-32.47.72.25
5001728Supersonic-60.111.53.34
6001555Supersonic-99.415.84.60
7001400Supersonic-153.320.96.08
8001266Transonic-224.826.87.80
9001155Transonic-318.133.89.82
10001072Subsonic-437.441.812.15

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.

Hunting Energy Reference

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.

Data & Sources

Your barrel, ammunition lot, and conditions will differ — always verify against the manufacturer's data and your own rifle.

Overview

The .257 Roberts is a mild-recoiling, inherently accurate quarter-bore that occupies a comfortable middle ground between varmint and big-game work. Lighter bullets make it a capable long-range varmint and predator round, while heavier 100- to 120-grain loads handle deer, pronghorn, and similar medium game cleanly at moderate ranges. It is well regarded for its pleasant manners, efficiency, and versatility, traits that earned it a devoted following among traditional hunters. Its main limitation is a relatively conservative factory loading history, since standard-pressure ammunition leaves velocity on the table; handloaders and +P offerings unlock its real potential. Though largely eclipsed commercially by the .243 Winchester and 6.5mm rounds, it remains a respected classic with a loyal niche among those who value refinement over raw power.

History

The .257 Roberts grew out of a wildcat developed in the 1920s by gunwriter and experimenter Ned Roberts, who necked the 7x57mm Mauser case down to accept .25-caliber bullets. Remington standardized and commercialized the cartridge in 1934, sharpening the shoulder angle from Roberts' original design. It earned a lasting reputation as one of the classic American "quarter-bore" cartridges, prized by hunters through the mid-20th century, and later gained new life with the higher-pressure +P loadings that helped it keep pace with modern rounds.

Related Cartridges

Learn the Fundamentals

Run this cartridge in the ballistic calculator · Compare it against another cartridge · How this data is produced