Nice different buy.

I've always found it unusual how that Swiss province requires such a large bore calibre with a rainbow trajectory. For hunting in a mountainous terrain.

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Copied:
Bullet weights for the 10.3 x 60 R Swiss generally range from 300 to 340 grains,

Muzzle velocities are modest by modern standards, generally in the 1350–1450 fps range, producing significant but manageable recoil

Calibre Specifications

Specifications
Standard / Datasheet

C.I.P.
Primer Size

Large Rifle Magnum (LRM)

Case Capacity

91 Grains of Water

Bullet / Barrel Diameter

0.413'' | 10.49 mm

Max. Case Length

2.392'' | 60.76 mm

Max. Cartridge Length

3.106'' | 78.89 mm

Max. Standardized Pressure:

39160 psi | 2700 bar

https://www.xxlreloading.com/caliber-load-data/10.3-x-60-r-swiss