7.5x55mm Schmidt-Rubin / 7.5mm Swiss (155/155.5 GR Berger Bullets Data)

7.5 × 55 mm Schmidt–Rubin / 7.5 mm Swiss (155 / 155.5 gr Berger Bullets Data)

The 7.5 × 55 mm Swiss (also known as the 7.5 mm Schmidt–Rubin) is a rimless, bottleneck rifle cartridge developed in Switzerland beginning around 1911. Standard issue in Swiss military rifles like the K11 and later the famed K31, it has earned a reputation among precision shooters for excellent ballistic consistency, superior brass quality, and tight chambering tolerances. Its official designation under Swiss service was “7.5 mm GP11” when loaded with the 174-grain full-metal-jacket boat-tail bullet; however, custom handloaders frequently use lighter match bullets such as the 155 or 155.5-grain offerings from for enhanced accuracy potential in this caliber.

When loaded with 155/155.5-grain Berger match projectiles, the 7.5 × 55 mm Swiss truly demonstrates its precision capabilities. Berger’s published data shows that these bullets perform optimally when paired with stable, medium-burn rate powders in brass sourced from reputable manufacturers (Norma, Prvi Partizan, etc.). For instance, one documented combination with the 155.5-grain Berger bullet and IMR-4350 achieved velocities in the 2,400-2,500 fps range, while maintaining sub-MOA group sizes in tightly chambered Swiss K31 rifles. Handloaders often report that this lighter bullet weight allows the rifle to reach its “sweet spot” with slightly higher velocity, flatter trajectory, and reduced wind drift without stepping into excessive pressure zones.

Reloading this dataset requires attention to several unique details. First, bore and groove dimensions in Swiss military barrels are typically .306" groove diameter, so bullet fit is critical; many loaders prefer sizing to .308" or .310" to ensure proper bore-engagement and consistent results. Second, the cartridge’s high brass quality and large case capacity relative to older mid-bore cartridges mean that case preparation (trimming, uniform neck tension, annealing where applicable) and priming consistency are essential to minimize standard deviation and spread. Third, because the GP11 generation military loads ran relatively modest pressures for the era (~50,000 psi), modern handloaders should treat published match data as benchmarks — aiming for consistent performance rather than jumping directly to maximum loads. Ladder testing, chronograph monitoring, and pressure sign inspection are strongly recommended.

In practical terms, shooters have found that with a well-tuned 155/155.5 gr Berger bullet in a Swiss K31 or custom 7.5×55mm rifle, the round is capable of exceptional accuracy: consistent sub-minute of angle groups at 100 yards (and strong ½ MOA potential when components are matched), minimal recoil compared to high-power magnums, and excellent brass durability when properly reloaded. Its ballistic synergy blends historical service-cartridge reliability with today’s match-grade component technology.

Whether you’re shooting target, doing light game hunting, or simply preserving a finely engineered vintage rifle, the 7.5 × 55 mm Swiss loaded with Berger match bullets offers an excellent platform. It demonstrates how an early 20th-century service cartridge retains relevance when precision development and component quality are applied.

Source: Berger Bullets match-bullet data & historical reloading guides referenced via Wolfe Publishing.