10mm Auto

.22 K-Hornet (P.O. Ackley Data)

The .22 K-Hornet (an improved version of the .22 Hornet) is a cartridge designed to refine the case geometry — steeper shoulder, reduced body taper — to enhance internal capacity and improve combustion efficiency. According to P.O. Ackley’s loading notes, these changes result in a cartridge that, when properly loaded, offers measurable velocity gains and more consistent accuracy compared to the standard Hornet.

Ackley’s data advises a conservative load development approach: although the case allows higher performance, he emphasizes starting well below standard Hornet maximums, meticulously checking brass for head expansion, inspecting primers, and using ladder testing to identify seating depth accuracy sweet spots. He notes that bullets in the 35 – 45-grain range tend to balance the improved geometry well, allowing the cartridge to perform effectively in varmint rifles while maintaining controlled recoil and good barrel life.

The loading philosophy further stresses that the improved case demands uniform brass preparation (trimming, deburring, annealing), consistent neck tension, and careful seating depth control. Because the sharper shoulder and increased capacity can make the cartridge more sensitive to bullet jump and powder lot variation, Ackley stresses that accuracy often depends more on load consistency than on chasing maximum velocity.

In practical terms, Ackley’s notes show that with optimal bullets and tuning, the .22 K-Hornet can achieve roughly 100-200 fps more than a standard Hornet load in similarly configured rifles — provided the reloader respects the tuning requirements and uses quality components. The design remains prized by precision handloaders for its efficiency, crisp performance, and adaptable nature.

Source: P.O. Ackley – Handbook for Shooters & Reloaders (Ackley’s load commentary and historical notes)