9.3mm BS / 9.3mm Barsness-Sisk

9.3 mm BS / 9.3 mm Barsness-Sisk

The 9.3 mm BS (Barsness-Sisk) is a modern wildcat cartridge developed by gunsmith Charlie Sisk and author John Barsness, designed to deliver 9.3 × 62-like performance in a shorter-action package. The concept necks the .350 Remington Magnum case up to 9.3 mm and re-chambers it for a fast-action rifle, giving shooters a potent combination of medium-bore power and compact rifle ergonomics.

According to a feature in Handloader Issue #237 – October 2005, the cartridge was tested in a custom Sisk-built Remington Model 700 with a 23" Lilja barrel. Loads detailed include bullets ranging from the 232-gr Norma Oryx to 286-gr Barnes TSX, achieving velocities from approximately 2,674 fps down to 2,410 fps depending on bullet weight and powder choice.

One of the stand-out loads from the testing used a 232-grain Norma Oryx at ~2,674 fps, showing sub-MOA dispersion in the test rifle. Another notable entry featured a 250-grain Barnes TSX achieving around 2,667 fps — impressive figures for a shortened, magazine-fed action. The article underscores the importance of bullet selection, chambering quality, and load development in realizing the full potential of this cartridge.

Reloaders working the 9.3 mm BS should pay special attention to forming and annealing brass (typically from the .350 Remington Magnum parent case), ensuring case concentricity, and selecting bullets optimized for deep penetration and reliable expansion — given the cartridge’s safari/hunting intended role. While the wildcat nature means no official SAAMI data exists, the Handloader article provides a responsible launch point and emphasizes chronograph validation, pressure checking, and conservative progression.

The Barsness-Sisk wildcat offers a compelling choice for shooters seeking a high-performing 9.3 mm platform with shorter action convenience, modern bullet availability, and excellent proven results — as long as handloaders respect the experimental nature of the cartridge. For accurate development, always begin with verified loads, log velocity and group data, and adapt to your own rifle’s behavior.

Source: Wolfe Publishing – Handloader Issue #237 (October 2005)