.22 CHeetah MKI

.22 Cheetah MKI

The .22 Cheetah MKI is a wildcat cartridge variant of the original Cheetah, refined to improve feeding geometry and case efficiency. In Handloader Issue #147 – September, 1990, the cartridge is examined with load data, test results, and performance notes that reveal how the MKI tweaks impact velocity, pressure, and accuracy.

The MKI version retains the same .224-inch bullet caliber as the original, with bullet weights typically in the 35 to 50 grain range. Propellants used in the published tests include those that burn cleanly and show stable velocity curves—some examples being H322, Benchmark, or IMR 4198. The test data shows how slight changes in case dimensions and shoulder angle affect internal ballistics and accuracy tuning.

A key takeaway from the article is the importance of case prep and component consistency. The MKI’s tighter tolerances amplify the effects of trimming, annealing, neck tension, and chamfering. Even small shifts in seating depth or bullet jump are shown to influence group size and pressure behavior. The article notes that optimal accuracy was often found with bullets seated just off the lands in the test rifles.

In terms of performance, the MKI showed improved stability over longer strings, with less drift in velocity and better retention of precision as the barrel heated. The article attributes this to better powder burn efficiency resulting from the improved geometry. When properly tuned, the MKI retained the best of its ballistics while offering less shot-to-shot variance in realistic use scenarios.

Though the .22 Cheetah MKI never saw widespread adoption, the Handloader 147 article preserves its developmental record. The MKI remains of interest to enthusiasts of precision wildcats, especially those working with custom rifles and modern components. Its blend of incremental refinement and performance potential ensures it remains a notable part of the Cheetah lineage.

Source: Handloader Issue #147 – September, 1990