Handloads: A .257 Ackley Improved Load Worth The Effort

by
posted on November 26, 2024
** When you buy products through the links on our site, we may earn a commission that supports NRA's mission to protect, preserve and defend the Second Amendment. **
.257 Ackley Improved Load
Design by David Labrozzi.

In his Handbook For Shooters And Reloaders (Volume 1), P.O. Ackley wrote of the .257 Ackley Improved that, “It is a relatively efficient cartridge, flexible and comes close to the mythical ‘all around cartridge.’”

.257 Ackley Improved Load specsTo make .257 Ack. Imp. cases requires fire-forming .257 Roberts cases in an Ackley Improved chamber; cases come out of the Improved chamber with a reduced body taper and increased shoulder angle. Be careful of this approach, though, as there are no established chamber dimensions for the .257 Ack. Imp. To fire-form empty Roberts cases, I loaded them with 10.0 grains of Bullseye powder—cases tamped full of Puff-Lon ballistic filler and a dab of glue on the case mouth to hold everything in place—and then fired them in my rifle’s Improved chamber. This method resulted in cases with 0.026" less case body taper, the body lengthened by 0.075" and the shoulder angle increased to 40 degrees. Fire-forming cases also shortened them in length a few thousands of an inch, but after four reloads, they still have not required trimming.

The Improved shape results in about a 7 percent total case capacity increase compared to the Roberts. Comparing my handloading records and loads from a couple of handloading manuals for both cartridges, .257 Ack. Imp. burns 12 percent to 17 percent more propellant than the Roberts to achieve 4 percent to 7 percent higher velocities.

Trustworthy load data is rather limited for the .257 Ack. Imp. The Nosler Reloading Guide 9, though, contains plenty of reliable information. Both H4895 and Reloder 15 perform well shooting bullets weighing up to 80 grains, and H4831, IMR 4350 and 4831 and Reloder 22 are excellent paired with heavier bullets. The recipe’s load of 49.0 grains of IMR 4350 fired Nosler 100-grain Ballistic Tips at 3,214 f.p.s. from the Montana Rifle Co.’s 24" barrel. That’s about a 200 f.p.s. increase above what the .257 Roberts will fire the same weight bullet—which makes forming Improved cases well worth the toil.

Latest

smith & wesson performance center model 19 carry comp moss
smith & wesson performance center model 19 carry comp moss

Unlocking The Future: Smith & Wesson's "No Lock" Revolvers

The future is shaping up to be a good one for fans of Smith & Wesson revolvers. The iconic American company had released 14 new models thus far in 2025 at the time this was written mid-year. And, with one exception, they have all shared a common feature—no internal lock.

The Armed Citizen® Oct. 6, 2025

Read today's "The Armed Citizen" entry for real stories of law-abiding citizens, past and present, who used their firearms to save lives.

FEMA Notes Decline In Disaster Preparedness

A recent report from the Federal Emergency Management Administration (FEMA) noted a decline in local government preparedness for natural disasters, putting increased pressure on individuals to prepare themselves for emergencies.

Army Announces Type Classification Of New Infantry Rifle, Machine Gun

In May 2025, the U.S. Army’s Soldier Lethality Project at the Picatinny Arsenal in New Jersey announced the official type classification of SIG Sauer’s M7 rifle and M250 automatic rifle, previously known as the XM7 and the XM250, respectively.

RXR22: Savage Arms Redefines The Budget Rimfire Rifle

Savage Arms has a long history of producing affordable and accurate rimfire rifles, but with its RXR22, the company is bringing a new level of affordability and modularity to rimfire rifle fans.

SARCO: A Lifetime Covered Up With Surplus Firearm Parts

When it comes to selling gun parts and gun-related military surplus, Charles “Cholly” Steen has been at it for longer than almost anyone. It all started when, as a 5-year-old, he began stashing odds and ends in the drawers of his clothes dresser.

Interests



Get the best of American Rifleman delivered to your inbox.