.257 Roberts Ackley Improved
Classic Ackley conversion that brings the mild .257 Roberts close to .25-06 speed. Deer and pronghorn rifle with light recoil.
Good for: Hunting, Ackley Improved
A typical factory load is a 117 gr soft point bullet at about 2,950 ft/s, with roughly 2,261 ft-lbs of energy at the muzzle.
Typical load
117 grsoft pointMuzzle speed
2,950 ft/sMuzzle energy
2,261 ft-lbsTypical BC (G1)
≈ 0.39typical, varies by brandTwist rate
1:10Practical range
350 ydPoint-blank range
286 yd6" vital zoneRecommended platform
Light or standard rifleLight recoil; fine in a 6–7 lb rifleOn the Wildcats chart
Made for
Classic Ackley conversion that brings the mild .257 Roberts close to .25-06 speed. Deer and pronghorn rifle with light recoil.
Typical load
117 grsoft point
Typical muzzle fps
2,950ft/s
Typical muzzle energy
2,261ft-lbs
Typical BC (G1)
≈ 0.39typical, varies by brand
Twist rate for typical load
1:10
Practical range
350 yd
MPBR
286 yd6" vital zone · Near zero 27 yd · Far zero 245 yd · Min PBR 0 yd · Max PBR 286 yd · Sight-in @100 2.63" high
Recommended platform
Light or standard rifleLight recoil; fine in a 6–7 lb rifle
Open the full Wildcats chart →
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Speed, energy and BC are typical figures for the listed load; real numbers vary by brand, lot and barrel length. Always check the ammo maker's data for your exact load.